Journal Sciences News
The Spine Journal
15 March 2018
Effect of chelating reagents on nanostructured CdS layer morphology in CdS-sensitized TiO2 solar cells by successive ionic layer adsorption and reaction (SILAR) method
Publication date: April 2018
Source:Materials Science in Semiconductor Processing, Volume 77 Author(s): Noshin Mir, Amir Abbas Mir, Pouya Karimi, Neda Poormolaei The chelating reagent is one of effecting factors which determines the properties of CdS films. Film morphology and roughness are very crucial in determining the further photovoltaic performance of the device. In this work, CdS film was synthesized by successive ionic layer adsorption and reaction (SILAR) method on FTO/TiO2 substrate. Different chelating reagents with N and S donating atoms were used in Cd2+ solution to investigate their effect on CdS film properties. X-ray diffraction spectroscopy (XRD), atomic force microscopy (AFM), ultraviolet-visible [1] spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy were used for characterization of the films. Quantum dot-sensitized solar cells (QDSCs) were fabricated by using different produced photoanodes and the photocurrent densityvoltage curves of the assembled solar cells were measured. Computational quantum chemistry methods were used for calculation of binding energy, topological properties between chelating reagents and CdS film. The HOMO and LUMO molecular orbitals were calculated and visualized. Experimental and theoretical results confirmed that the ligand containing S donating atom results in formation of CdS film with the lowest surface roughness and the highest photovoltaic conversion efficiency compared to the other ligands.
15 March 2018
Investigation of the structural and optical properties of the CdSe/Yb/CdSe interfaces
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): S.R. Alharbi In the current study, we report the effect of the ytterbium nanosandwiching on the structural, optical and dielectric properties of the CdSe thin film. The Yb nanosandwiched layer thickness is varied in the range of 10200nm. The structural analysis which was carried out by the X-ray diffraction technique has shown that while the grain size increases, the strain, the defect density and the stacking faults are all decreases with increasing Yb thickness in the range of 10100nm. Further increase in the Yb thickness to 200nm decreased the grain size and increased the values of the other structural parameters. Optically, the CdSe absorbability increased 2.6 times at 1.41eV and the energy band gap redshifts with increasing Yb slab thickness reaching a value of 1.29eV for a slab thickness of 200nm. On the other hand, the dielectric spectra displayed two peaks at 2.11 and 1.60eV for the double layer CdSe films. These two peaks which were assigned to the exciton and electronic transitions, respectively, are observed to redshifts with increasing Yb slab thickness.
15 March 2018
Large-scale synthesis of ZnO nanostructures by pulse electrochemical method and their photocatalytic properties
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Anna Ulyankina, Igor Leontyev, Marina Avramenko, Denis Zhigunov, Nina Smirnova In this paper, we report a simple environment-friendly and large-scale approach to synthesis of highly crystalline zinc oxide nanostructures using pulse alternating current (PAC). The morphological results demonstrate flower-like architectures of nanoparticle-based and nanorod-based zinc oxide (ZnO-NPs and ZnO-NRs) obtained in KCl and NaCl as electrolytes. The photocatalytic activity of the obtained materials was performed in methylene blue dye degradation reaction under UV light irradiation. A high efficiency of ~ 90% within 60min with excellent rate constant (k = 0.0386min
15 March 2018
Hierarchical CuInS2 synthesized with the induction of histidine for polymer/CuInS2 solar cells
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Wenjin Yue, Feiyu Wei, Yang Li, Lian Zhang, Qun Zhang, Qiquan Qiao, Hui Qiao Hierarchical CuInS2 (H-CuInS2) was synthesized with the induction of histidine by the solverthermal method. The factors such as the category of the amino acid, the molar-quantity of histidine, the solvent, reaction time and reaction temperature were observed. The products were characterized by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and ultraviolet-visible absorption spectrum. The results showed that, histidine is proven to be effect to synthesize the uniform flower-like chalcopyrite H-CuInS2 in the solvent of N,N-dimethyl formamide at 180C for 24h, which is originated from the strong coordinate ability of histidine. The change in the molar-quantity of histidine would result in the obviously different sizes and micro-structures of H-CuInS2, contributing to the different light-harvesting ability and fluorescence quenching efficiency to poly (2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene) (MEH-PPV). As a result, polymer solar cells with MEH-PPV and different H-CuInS2 displayed structure-dependent device performances, device based on small-sized H-CuInS2 obtained higher energy conversion efficiency of 0.59% under the monochromatic illumination of 15.85mW/cm2 with wide spectrum response from 300 to 900nm.
15 March 2018
Visible active gold/carbon co-doped titanium dioxide photocatalytic nanoparticles for the removal of dyes in water
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Pardon Nyamukamba, Lilian Tichagwa, Omobola Okoh, Leslie Petrik Gold/carbon co-doped TiO2 photocatalysts with different contents of gold were prepared using a wet chemical technique, immobilized on fused silica and tested for their photocatalytic activity using methyl orange under visible light. Co-doping significantly red shifted the absorption edge of the photocatalysts. The synergistic effects between gold and carbon were best when the Au content was 1.0% where the lowest band gap of 2.45eV and high photocatalytic activity towards methyl orange were achieved. Co-doping was also found to promote anatase to rutile phase transformation and the highest transformation was achieved by using 0.5% of Au. The effect of the simultaneous photodegradation of methyl orange and bisphenol A was also studied and it was observed that the photodegradation rates achieved for each contaminant was reduced in the bi-component system when compared to the mono-component system.

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15 March 2018
Influence of silver incorporation on CZTSSe solar cells grown by spray pyrolysis
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Mohamed H. Sayed, Johannes Schoneberg, J
15 March 2018
Simple method for significant improvement of minority-carrier lifetime of evaporated BaSi2 thin film by sputtered-AlOx passivation
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): N.M. Shaalan, K.O. Hara, C.T. Trinh, Y. Nakagawa, N. Usami A novel surface passivation of AlOx on BaSi2 thin films fabricated by vacuum evaporation for solar cell application has been developed. The minority-carrier lifetime of evaporated BaSi2 film is shorter than that of epitaxial film. This lifetime has been improved by forming AlOx passivation layer on the BaSi2 surface by RF sputtering of Al followed by oxidation in air. A drastic improvement of the lifetime upon the passivation of AlOx was observed up to 15
15 March 2018
Structural and optical properties of silica single-layer films doped with ZnS quantum dots: Photoluminescence monitoring of annealing-induced defects
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Boukhalfa Belache, Youcef Khelfaoui, Mohamed Bououdina, Tewfik Souier, Weiping Cai Zinc Sulfide (ZnS) quantum dots (QDs) embedded in sol-gel silica single-layer films were synthesized by dip-coating and thermal treatment. Nucleation and growth of these QDs occurred during annealing. The effect of annealing temperature on morphological, structural and optical properties of the films was considered in the range (200500C). Scanning electron microscopy (SEM), atomic force microscopy (AFM), grazing incident angle X-ray diffraction (GIXD), UVVisible spectroscopy (UVVis) and photoluminescence (PL) were used to characterize the films. The band gap values of the ZnS QDs ranged from 3.83 to 4.03eV corresponding to average radii in the range 1.52.1nm. PL revealed different annealing-induced defects in the ZnS QDs. Zn interstices dominate at 400 and 500C annealing temperatures by the appearance of two excitation bands at 395nm and 404nm respectively. Corresponding emission bands were recorded at 402nm and 408nm. An emission peak (457nm) and an excitation peak (437nm) were also observed at 500C. These peaks were attributed to S vacancies which might be created by the transformation of ZnS to ZnO. Finally, an overall energy-level diagram showing all the defect states in the gap of ZnS was proposed.
15 March 2018
Fabrication of Cu2(ZnxMg1-x)SnS4 thin films by pulsed laser deposition technique for solar cell applications
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): G.L. Agawane, S.A. Vanalakar, A.S. Kamble, A.V. Moholkar, J.H. Kim In this study, the pulsed laser deposition technique was applied for the preparation and characterization of Cu2(Zn x Mg1-x )SnS4 (CZMTS) thin films for solar cell applications. The effects of various zinc/magnesium compositional ratios on the properties of the CZMTS thin films were investigated. The field emission scanning electron microscopy studies revealed that the CZMTS thin films exhibited dense, uniform and smooth surfaces. The X-ray diffraction studies on the as-deposited and annealed CZMTS thin films showed the prominent peak from the (112) plane for kesterite phase Cu2ZnSnS4. The Raman studies on the CZMTS thin films further confirmed formation of kesterite phase and beneficial MoS2 layer. Further, the Hall measurement studies on CZMTS thin films confirmed p-type electrical conductivity behavior. The conductivity increased from 2.31S/cm to 7.98S/cm with increased Mg concentration. The X-ray energy dispersive spectroscopy studies revealed formation of stoichiometric thin films. The direct optical band gap for the CZMTS thin films were found to be in the range of 1.31.5eV, suggesting their potential application as a low cost and earth abundant thin film solar cell absorber material.
15 March 2018
Sputtering based synthesis of CuO nanoparticles and their structural, thermal and optical studies
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Monu Verma, Vinod Kumar, Akash Katoch In the current research, we report the synthesis of CuO nanoparticles using dc reactive magnetron sputtering technique at various sputtering pressure (10, 20, 30, 40 and 50mTorr) and their structural, thermal and optical properties. The characterization of the synthesized CuO nanoparticles was carried using powder XRD, Raman spectroscopy, FT-IR, FE-SEM, EDX, TEM, TGA and UVvis DRS. XRD results exhibited the monoclinic phase of CuO nanoparticles and the crystallite size increases with increase in sputtering pressure. The EDX and Raman analysis confirm the formation of high purity CuO nanoparticles. The particle size of synthesized nanoparticles was calculated using TEM analysis. The FE-SEM and TEM results show spherical morphology in aggregated form. TGA results reveal that nanoparticles are purely hydrous and weight loss was inversely correlated to the particle size. UV-DRS results indicated that the band gap energy decreased with increase of sputtering pressure due to increase in particle size.
15 March 2018
Self-powered GaN ultraviolet photodetectors with p-NiO electrode grown by thermal oxidation
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Liuan Li, Zhangcheng Liu, Lei Wang, Baijun zhang, Yang Liu, Jin-Ping Ao Self-powered ultraviolet photodetectors based on n-GaN and p-NiO were fabricated through thermal oxidation. The transparent NiO was mainly dominated by [111] texture with an optical band gap of approximately 3.69eV. Compared with the conventional Ni/GaN photodetector, the p-NiO/GaN heterostructure photodetector possess a larger turn-on voltage and a smaller dark current because of the relatively higher effective barrier height. At an external bias of 0V, the photo responsivity and the UV to visible rejection ratio of the NiO/GaN photodetector are enhanced to 0.15A/W and 406, respectively. The improvement in UV photodetector performance is attributed to that the depletion region in NiO/GaN heterostructure can effectively eliminate the trapping charge carriers at the metal/semiconductor interface. The high-performance NiO/GaN photodetectors without driving power are potential for portable UV detectors application.
15 March 2018
Air annealing induced growth of self-assembled ultra long ZnS microwire: Structural and photoluminescence studies
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): S. Bhattacharyya, Biswajit Ghosh, Subrata Das In an attempt to facilitate annealing assisted self assembly, we have grown amorphous ZnS films using rapid vacuum evaporation technique and followed by air annealing at an elevated temperature for longer duration. It has been found that ultra long microwires were formed as a consequence of air annealing assisted asymmetric mass flow. However on further increase in annealing temperature the microwires were found to be squeezed, forming larger macromolecules. XRD studies revealed the gradual transition from amorphous to crystalline phase with preferential orientation along (008) hexagonal phase. Photoluminescence studies revealed multiple defect transition caused by annealing.
15 March 2018
Castor oil and olive oil-capped In2S3 and CuInS2 nanoparticles from xanthate complexes
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): Siphamandla C. Masikane, Neerish Revaprasadu The study investigates castor oil and olive oil as eco-friendly capping agents of
1 March 2018
Influence of substrate bias voltage on crystallographic structure, optical and electronic properties of Al/(Ta2O5)0.85(TiO2)0.15/p-Si MIS Schottky barrier diodes fabricated by dc magnetron sputtering
Publication date: 15 March 2018
Source:Materials Science in Semiconductor Processing, Volume 76 Author(s): M. Chandra Sekhar, N. Nanda Kumar Reddy, B. Purusottam Reddy, B. Poorna Prakash, Harish Sharma Akkera, S. Uthanna, Si-Hyun Park Thin films of (Ta2O5)0.85(TiO2)0.15 were prepared on p-Si and quartz substrates by reactive magnetron sputtering and the influence of substrate bias voltage (V b ) on their structural and electrical properties was studied. The crystal structure of the prepared films was elucidated by X-ray diffraction (XRD) studies. The structure of the as deposited films was found to be amorphous and the surface roughness of the films was found to be low. The crystallinity of the films was observed to be improved by increasing the substrate bias voltage. The XPS results revealed that the composition of the films were nearly stoichiometric with V b at 0V and
1 March 2018
Novel method for dry etching CH3NH3PbI3 perovskite films utilizing atmospheric-hydrogen-plasma
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Hayk Khachatryan, Hyeong-Pil Kim, Sung-Nam Lee, Han-Ki Kim, Moojin Kim, Kyoung-Bo Kim, Jin Jang Patterning of organic-inorganic hybrid methyl ammonium lead iodide (CH3NH3PbI3) perovskite films by atmospheric hydrogen plasma is explored. It is estimated that among oxygen, nitrogen, and hydrogen plasmas only the hydrogen plasma treatment is capable to etch perovskite film. A rectangular metal mask is placed to a perovskite film to form a mesa structure. The morphology of treated film is dramatically changed from metal mask to outward direction. In the patterned area eight regions are observed possessing different morphologies. The microstructures and compositions of the plasma-processed semiconducting films are analyzed in each region.

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1 March 2018
Morphology transformation from titanate nanotubes to TiO2 microspheres
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): A.H. Zaki, Aya El-Shafey, Sara M. Moatmed, Rahma A. Abdelhay, Esraa F. Rashdan, Romisaa M. Saleh, Mohamed Abd-El Fatah, Marwa M. Tawfik, Mohamed Esmat, S.I. El-dek Single phase TiO2 mesoporous microspheres were synthesized using a facile one step technique from nanotubes. The prepared microspheres were crystallized in an anatase form with a tetragonal symmetry. The results of surface area measurements revealed mesoporous structure of such materials together with uniform pores. The samples possess rough surface and could be exploited in different applications. The methodology is easy, cheap, fast and could be reproduced for morphology tuning and/or transition.

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1 March 2018
Influence of 100keV Ar+ implantation on electrical and optical properties of TiO2/Ag/TiO2 multilayer films
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Satyavir Singh, Vikas Sharma, Dinesh Saini, Surbhi Shekhawat, K. Asokan, Kanupriya Sachdev The objective of this study was to investigate the effect of 100keV Ar+ ion implantation with fluence ranging from 1
1 March 2018
Substrate temperature dependent structural orientation of EBPVD deposited NiO films and its influence on optical, electrical property
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Sushil Kumar Kuanr, G. Vinothkumar, K. Suresh Babu The structural, electrical and optical property of nickel oxide thin films deposited by electron beam physical vapour deposition were investigated with respect to substrate temperature (T s = 100, 300, and 450C). In spite of the amorphous nature of the substrate (quartz), depending on the substrate temperature either a preferred or polycrystalline NiO growth was observed. A (200) preferential orientation resulted at 100C while at 300 and 450C the NiO films were oriented along (111) and (220) planes. The NiO films obtained at Ts = 100C was highly transparent compared to the polycrystalline films due to the low light scattering of (200) film. The conductivity of NiO films measured at 100C was found to be three orders higher than the films obtained at T s = 450C. Thus, the orientation was found to be influencing optical and electrical properties of NiO films.

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1 March 2018
Growth and properties of one-dimensional
1 March 2018
Importance of precursor type in fabricating ZnO thin films for photocatalytic applications
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Vinoth Kumar Jayaraman, Agileo Hern
1 March 2018
Control of polysilicon nanowires conductivity by angle-dependent ion implantation
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Shahar Aziza, Alex Ripp, Dror Horvitz, Yossi Rosenwaks Boron doped polysilicon nanowire devices were fabricated using lithography-based top-down method. The devices, implanted by boron ions at different angles (0,20,30,45), exhibited significant dependence of electrical conductivity on incident implantation angle. Monte Carlo simulations of the dopant distribution, show that the projected range of boron implant increase with decreasing incident angle, in agreement with literature SRIM (Stopping and Range of Ion in Matter) reported data. The simulations and electrical measurements, show that geometrical shadowing reduce the device conductivity, while lower incident implantation angles increase it. This implies that Polysilicon Nanowires conductivity can be controlled by changing the implant angle, and this is beneficial for top=down fabrication of SiNW sensors based on accumulation and depletion.
1 March 2018
Structural analysis of polycrystalline silicon thin films produced by two different ICPCVD approaches
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Zhongli Li, Ayra Jagadhamma Letha, Jia-Fu Wei, Man-Ling Lu, Yijian Liu, Huey-Liang Hwang, Yafei Zhang The structural properties of polycrystalline Si (poly-Si) thin films formed by using ICPCVD and LIA-ICPCVD methods under different H dilution ratios were investigated. Columnar-structured poly-Si films with 82% crystalline volume fraction were obtained by ICPCVD at a lower H dilution ratio of 50%. In the case of LIA-ICPCVD, to obtain nearly the same crystalline volume fraction (80%), a higher H dilution ratio (98%) was required and the poly-Si films obtained were mostly of cone-shaped columnar structure. The reverse effect is due to the difference in the antenna design in these systems, which changes the plasma characteristics. Multilayer deposition process, and subsequent H treatment and annealing were used in ICPCVD for producing highly crystallized poly-Si thin films from microcrystalline Si films. In the case of LIA-ICPCVD, annealing the ITO coated glass substrate in the deposition chamber prior to Si:H film deposition together with the optimization of process pressure yielded highly crystalline poly-Si film.
1 March 2018
Synthesis of mesoporous In2O3 nanocubes and their superior trimethylamine sensing properties
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Su Zhang, Peng Song, Zhebin Tian, Qi Wang Mesoporous In2O3 nanocubes were successfully synthesized via a facile and low-cost hydrothermal method. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption-desorption analyses. The results reveal that mesoporous In2O3 nanocubes with a size range of 3060nm, possess plenty of pores, and average pore size is about 5nm. It is important that the In2O3 nanocubes with mesoporous structure have large specific surface area, which leads to higher response to trimethylamine (TMA). The response value to 10ppm TMA is 57 at an operating temperature of 160C, and the response and recovery time are 4 and 11s, respectively. It is expected that the mesoporous In2O3 nanocubes with large specific surface area and excellent sensing properties will become a promising functional material in monitoring and detecting TMA.
1 March 2018
Microstructure influenced variation in the local surface electrical heterogeneity in thickening Al-doped ZnO films: Evidence using both scanning tunnelling spectroscope and conductive atomic force microscope
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Tvarit A. Patel, Chetan C. Singh, Emila Panda In this study, variation in the local surface electrical heterogeneity within and also for a thickening Al-doped ZnO film is studied using both the Conductive atomic force microscope/Spectroscope (C-AFM/C-AFS) and Scanning Tunnelling Microscope/Spectroscope (STM/STS) techniques. To this end, these films were deposited by varying the deposition time from 15 to 120min by RF magnetron sputtering. The local surface electrical heterogeneity was found to be strongly dependent on the overall microstructure of the film grown at a particular deposition time. X-ray Photoelectron Spectroscope (XPS) and Transmission Electron Microscope-Energy Dispersive Spectroscope (TEM-EDS) were used to discern the distribution of the chemical constituents over these film surfaces. This study correlates the presence of a large amount of chemisorbed oxygen and/or segregated AlxOy at the grain boundaries associated with relatively non-uniform and/or rough films to the overall lower surface current values. Subsequently, a uniformly thick AZO film with a homogenous microstructure grown at an optimum deposition time is found to have the least amount of chemisorbed oxygen along with an effective distribution of Al doping on the film surface, leading to an increase in the overall surface current. This higher surface current is then found to increase the surface electrical heterogeneity of the film due to increased difference between a defect and defect-free region, contrary for a non-uniform and/or rough film.
1 March 2018
Using silicon nanoparticles to modify the surface of graphene nanosheets
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Marzieh Savadkoohi, Davoud Dorranian, Elmira Solati In this work, the synthesis and properties of the graphene/silicon nanocomposites as a function of volumetric ratio of Si nanoparticles and graphene nanosheets suspensions has been investigated experimentally. Firstly the silicon nanoparticles and graphene nanosheets suspensions were synthesized by pulsed laser ablation method with Q-switched Nd:YAG laser. Then the mixture samples with different volumetric ratio of the graphene and Si suspensions were irradiated with UV radiation. UVVisNIR spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectrum, potential and dynamic light scattering, and photoluminescence spectra were used to characterize the ablation products and graphene/silicon nanocomposites produced by UV irradiation. Results confirmed the successful production of silicon nanoparticles and graphene nanosheets, and also formation of graphene/silicon nanocomposites. According to the results, with increasing the concentration of graphene nanosheets in the suspensions the surface morphology of the graphene/silicon nanocomposites was exfoliated. Zeta potential implies that the suspension of samples with higher concentration of graphene nanosheets is more stable.
1 March 2018
Improving the efficiency of a Cu2ZnSn(S,Se)4 solar cell using a non-toxic simultaneous selenization/sulfurization process
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Li-Ching Wang, Yi-Cheng Lin, Hung-Ru Hsu This paper proposes a simple non-toxic simultaneous selenization/sulfurization process to improve cell efficiency in Cu2ZnSn(S,Se)4 (CZTSSe) solar cells with the aim of modulating the S/(S+Se) ratio. Experiment results show that the S content in the thin film increases with the S/(S+Se) ratio, and the S content on the surface is higher than inside the device when S/(S+Se) ratio
1 March 2018
Enhancement of electrical properties of flexible ITO/PET by atmospheric pressure roll-to-roll plasma
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Masoud Shekargoftar, Richard Krumpolec, Tom
1 March 2018
Magnetically recoverable B,F,P-TiO2/Fe3O4 nanophotocatalyst with enhanced charge separation efficiency
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Hongquan Jiang, Fang Zhao, Shuying Zang A magnetically recoverable B,F,P-TiO2/Fe3O4 nanophotocatalyst was prepared via a microwave-hydrothermal process and subsequent calcination after grinding B,F,P-TiO2 and Fe3O4 nanosheets in an agate mortar. The synergetic effects of B,F,P-tridoping and Fe3O4 coupling on promoting the photogenerated charge separation of TiO2 were confirmed by photoluminescence spectroscopy (PL), surface photovoltage spectra (SPS), and electrochemical impedance spectroscopy (EIS). B,F,P-TiO2/Fe3O4 exhibited typical superparamagnetic behavior and sufficient magnetic recycling property, as well as excellent photoactivity for the degradation of 4-chlorophenol (4-CP) under simulated sunlight irradiation (K app = 1.1
1 March 2018
Research on the thermal expansion of AgGa1
1 March 2018
Diffusion doping of germanium by sputtered antimony sources
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Gianluigi Maggioni, Francesco Sgarbossa, Enrico Napolitani, Walter Raniero, Virginia Boldrini, Sara Maria Carturan, Daniel Ricardo Napoli, Davide De Salvador Antimony sputter deposition and subsequent diffusion annealing in controlled atmosphere was implemented on Ge wafers, for achieving an optimized n+ doping aimed at the final application of these doped contacts to Ge-based radiation detectors. Two approaches were adopted for n+ doping: diffusion from Sb source sputtered directly on the Ge surface, and diffusion from a remote dopant source. Surface morphology was specifically investigated by electron (SEM-EDS) and atomic (AFM) microscopies. Diffusion profiles were characterized by Secondary Ion Mass Spectrometry (SIMS). The remote doping, obtained by using a Sb-coated Si wafer placed close to the Ge substrate during the diffusion annealing, allowed to attain defect-free surface morphologies and diffusion profiles compatible with well assessed equilibrium diffusion models.
1 March 2018
Manufacturing and electrical characterization of Al-doped ZnO-coated silicon nanowires
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Ahmet Kaya, K. Gurkan Polat, Ahmed S. Mayet, Howard Mao,
1 March 2018
Investigation of fur-like residues post dry etching of polyimide using aluminum hard etch mask
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Shivani Joshi, Angel Savov, Salman Shafqat, Ronald Dekker The authors found that oxygen plasma etching of polyimide (PI) with aluminum (Al) as a hard-etch mask results in lightly textured arbitrary shaped fur-like residues. Upon investigation, the presence of Al was detected in these residues. Ruling out several causes of metal contamination that were already reported in literature, a new theory for the presence of the metal containing residues is described. Furthermore, different methods for the residue free etching of PI using an Al hard-etch by using different metal deposition and patterning methods are explored. A fur-free procedure for the etching of PI using a one step-reactive ion etch of the metal hard-etch mask is presented.
1 March 2018
Influence of the mesa electrode position on monolithic on-chip series-interconnect GaAs laser power converter performance
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): ChengGang Guan, Wen Liu, Qian Gao Monolithic on-chip series-interconnect (MOS) technology is the most mature technology for the fabrication of muti-junction laser power converters. In this study, we focused on the effect of mesa electrodes prepared at different positions on the GaAs laser power converter performance. First, an optimized epitaxial structure was prepared, and then, two different structure six-junction MOS laser power converters were separately fabricated. The test results that structure1 which mesa electrode at the base layer has 41.5% efficiency compare to structure2 which at the lateral conduction layer (LCL)has 37.4% efficiency. The characteristic data statistics of the 95 samples with two structures indicated that structure1 produces a higher output power and exhibits better performance characteristics. According to the theoretical models of the two structures, the root cause is that structure1 has a lower series resistance. Additional simulated results show that when the base doping concentration is higher than 5.1
1 March 2018
Formation of black silicon using SiGe self-assembled islands as a mask for selective anisotropic etching of silicon
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): D.V. Yurasov, A.V. Novikov, M.V. Shaleev, N.A. Baidakova, E.E. Morozova, E.V. Skorokhodov, Y. Ota, A. Hombe, Y. Kurokawa, N. Usami Simple technique of formation of black silicon using wet chemical etching of crystalline Si wafers with SiGe self-assembled islands is proposed. The main idea consists of the utilization of SiGe islands as a mask for wet anisotropic etching of Si in alkali-based solution at the first etching stage and further removal of SiGe residuals by etching in a HF:H2O2:CH3COOH mixture at the second etching stage. Initial samples were the crystalline Si wafers with SiGe islands formed on them by deposition of 2.514nm of Ge at 800C. After the two above-mentioned etching steps a submicron relief on a Si surface was formed. Investigation of optical properties of fabricated structures revealed significant decrease of reflection (AM 1.5G weighted reflection ~23%) and increase of absorption in the wavelength range of 5001200nm. Due to the very small amount of Si removal (<0.5m), utilization of standard chemicals for Si-based solar cell technology and potential suitability for usage in large-scale manufacturing the proposed technique is promising for increasing of efficiency of thin wafers crystalline Si solar cell.
1 March 2018
Optimization of TiO2/ZnO bilayer electron transport layer to enhance efficiency of perovskite solar cell
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Nitu Kumari, Jignasa V. Gohel, Sanjaykumar R. Patel In the present study, TiO2/ZnO bilayer as electron transport layer is optimized and used to design a perovskite solar cell. This bilayer helps in high electron extraction and low interfacial recombination. TiO2 films are prepared using spray pyrolysis techniques on fluorine doped tin oxide substrate. The deposition parameters are optimized using parametric study as well as using the Taguchi optimization technique. ZnO is used as other part of electron transport bilayer to reduce the charge recombination. The thickness of prepared TiO2 film obtained at Taguchi optimum condition (103nm) is lower than that of obtained at parametric optimum condition (147nm). At optimum conditions, the optical band gaps are in the range of 3.203.25eV. The prepared TiO2 films are consequently applied in perovskite solar cell preparation. 4-tert-butylpyridine is used with PbI2 to increase the stability of the perovskite solar cell. In addition, spiro-OMeTAD and Pt- fluorine doped tin oxide are used as hole transport material and counter electrode, respectively. The power conversion efficiency of the device at optimum conditions (parametric (D 5 ) and Taguchi (D 9 )) has been found as 5.59% and 6.51%, respectively. The power conversion efficiency of the device using 4-tert-butylpyridine as stabilizer has been found as 7.39% (D 11 ), which is highest among all devices. Current density (J sc ), open circuit voltage (V oc ) and the fill factor obtained for the device (D 11 ) are 17.87mAcm
1 March 2018
Anneal induced transformations of defects in hadron irradiated Si wafers and Schottky diodes
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): E. Gaubas, T. Ceponis, L. Deveikis, D. Meskauskaite, J. Pavlov, V. Rumbauskas, J. Vaitkus, M. Moll, F. Ravotti In this research, the anneal induced transformations of radiation defects have been studied in n-type and p-type CZ and FZ Si samples, irradiated with relativistic protons (24GeV/c) and pions (300MeV/c) using particle fluences up to 3
1 March 2018
Effect of post-annealing on the properties of thermally evaporated molybdenum oxide films: Interdependence of work function and oxygen to molybdenum ratio
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Baichao Han, Ming Gao, Yazhou Wan, Yong Li, Wenlei Song, Zhongquan Ma Molybdenum oxide (MoOx, x < 3) thin films were deposited on glass and (100) silicon substrates by thermal evaporation technique. Post-annealing of the samples was performed in O2 by rapid thermal process at 373673K. The surface chemical, structural
1 March 2018
Residual stresses in multi-crystalline silicon photovoltaic wafers due to casting and wire sawing
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): V. Pogue, S.N. Melkote, S. Danyluk A significant portion of the total manufacturing cost of crystalline silicon solar cells is attributed to the manufacturing and material costs of the silicon wafer. In addition to its high cost, silicon is very brittle, therefore wafers are prone to fracture during handling and processing. In this paper we investigate the manufacturing-induced residual stresses in photovoltaic silicon wafers due to casting and wire-sawing processes which affect the mechanical integrity of the wafers. Specifically, the paper addresses measurement of residual stresses in multi-crystalline silicon (mc-Si) wafers by photoelasticity and polarized micro-Raman spectroscopy methods, as well as the effects of diamond wire sawing and loose abrasive slurry sawing on the residual stresses within the grains and at the grain boundaries. The micro-Raman method probes the residual stresses in the near-surface of the wafer while the photoelasticity technique probes the through-thickness residual stress in the wafers. The results show that diamond wire sawing and loose abrasive slurry wire sawing produce compressive residual stresses in the as-cut mc-Si wafer surface. Loose abrasive slurry wire sawing produces larger compressive stresses in the as-cut surface layers compared to diamond wire sawing. Beneath the saw damage layer in the sawn wafers, low residual tensile stresses are present from the casting process.
1 March 2018
Heterojuncted non-metal binary composites silicon carbide/g-C3N4 with enhanced photocatalytic performance
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Fei Chang, Jiaojiao Zheng, Xiaofang Wang, Quan Xu, Baoqing Deng, Xuefeng Hu, Xiaoqi Liu Novel visible-light-driven silicon carbide (SiC)/g-C3N4 heterojuncted composites were successfully prepared via a facile ultrasonic dispersion and calcination method, and afterwards characterized by a couple of technologies including XRD, SEM, TEM, FT-IR, XPS, UVvis DRS, PL spectra, and N2 adsorption-desorption. It was found that SiC nanoparticles were uniformly deposited over the surface of g-C3N4 to create heterojunction domains along phase interface boundary, favoring charge carriers transfer and separation across the straddling band alignments. Besides, the visible-light absorption capability of samples was enhanced by the incorporation of SiC. These physiochemical merits ensured the improved photocatalytic performance of heterojuncted composites over the degradation of dyes rhodamine B (RhB) and methyl orange (MO) in comparison to each single component SiC or g-C3N4. Upon an identical condition, the sample SN8 exhibited the highest photocatalytic ability among all tested samples. According to active species trapping measurements,
1 March 2018
Application of a novel triple metal-nonmetal doped TiO2 (K-B-N-TiO2) for photocatalytic degradation of Linear Alkyl Benzene (LAB) industrial wastewater under visible light
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): H. Zangeneh, A.A. Zinatizadeh, M. Feyzi, S. Zinadini, D.W. Bahnemann In this work, novel triple metal-nonmetal doped TiO2 (K-B-N-TiO2) was synthesized by the solgel method. The structure and properties of the synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. Photocatalytic activity of the nanoparticles was assessed by degradation of linear alkyl benzene (LAB) industrial wastewater at different operating conditions. The effects of initial pH, photocatalyst loading, initial COD concentration and reaction time on the photocatalytic performance of the nanoparticles degrading LAB wastewater were determined by response surface methodology (RSM). The region of examination for the process was taken as the area enclosed by initial COD concentration (200500mg/l), catalysis loading (12g/l), initial pH (311) and reaction time (18h). The doping modes reduced recombination of photogenerated electrons and holes, and extended the absorption of TiO2 into the visible light. The photocatalyst properties of K-B-N-TiO2 were more effective than those of pure TiO2 and other modified single and double doped TiO2 (B-N, K-N, N, B and K-TiO2). The COD removal efficiencies by the photocatalysis were increased from pure TiO2 to multi-doped TiO2 in the following order; multi-doped TiO2 > single-doped TiO2 > pure TiO2. More than 55% and 81% of COD content of the LAB industrial wastewater was mineralized under visible light and UV irradiation, respectively at optimum condition (COD of 200mg/l, catalyst loading of 1.5g/l and pH of 3). The BOD5/COD ratio for the remaining COD was obtained to be about 0.4 which indicates higher biodegradability of the treated effluent in comparison with the raw wastewater.
1 March 2018
Gold nanoparticles coated silicon nanowires for efficient catalytic and photocatalytic applications
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Sonia Amdouni, Yacine Cherifi, Yannick Coffinier, Ahmed Addad, Mohamed Ali Za
1 March 2018
Thermal annealing of SnS thin film induced mixed tin sulfide oxides-Sn2S3 for gas sensing: Optical and electrical properties
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Shiamaa A. Zaki, M.I. Abd-Elrahman, A.A. Abu-Sehly, N.M. Shaalan, M.M. Hafiz This work reports the air-annealing effect on the structure, optical and electrical properties of tin sulfides (SnS) thin films and the capability of using these films for gas sensing application. The X-ray diffraction investigation shows that the predominant phase SnS (040) plane for the as-deposited film changes into Sn2S3 (201) plane after annealing. Furthermore, the annealed films at high temperatures (533 and 553K) are partially oxidized leading to the formation of mixed tin sulfide oxides-Sn2S3 (MTO-Sn2S3) heterostructure thin film. The optical constants and thickness of films are calculated using Swanpole's method. Both optical band gap and electrical activation energy increased after annealing in the range (493553K) for 0.5h in ambient air. Optical and electrical results indicate the existence of mixed phase characteristics of studied films. The gas sensing properties of MTO-Sn2S3 composite are investigated for methane gas detection. The fabricated sensor exhibits a weak sensitivity at low operating temperatures (50 and 100C). The sensitivity improves at high temperatures reaching its maximum at 250C. At 250C the response and recovery times are 250 and 82s, respectively.
1 March 2018
Physical properties of solution processable n-type Fe and Al co-doped ZnO nanostructured thin films: Role of Al doping levels and annealing
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): A. Goktas, F. Aslan, B. Ye
1 March 2018
Facile synthesis of earth-abundant and non-toxic p-type Si96B4/SiCp nanocomposites with enhanced thermoelectric performance
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Naval Kishor Upadhyay, L.A. Kumaraswamidhas, Bhasker Gahtori, Saravanan Muthaiah, Sivaiah Bathula, Radhey Shyam, Ajay Dhar One of the impediments in the development of thermoelectric devices for power generation is that they mostly contain toxic and expensive elements and/or are synthesized using expensive or time-consuming material processing methodology. We report the synthesis of SiliconBoron (Si96B4) alloy employing earth abundant constituent element using a facile single-step reactive sintering using spark plasma sintering technique. In order to enhance its mechanical properties, the synthesized Si96B4 alloy was dispersed with SiC nanoparticles and the effect of its addition on the thermoelectric and mechanical properties in the resulting Si96B4/SiC nanocomposite has been investigated. A thermoelectric figure-of-merit ZT ~ 0.27 at 1123K was realized at an optimized composition of Si96B4/1wt% SiC nanocomposite. This enhancement in ZT primarily originates from a noticeable reduction in the thermal conductivity on SiC dispersion in Si96B4 alloy, owing to the scattering of heat-carrying phonons by nanoscale SiC particles and mesoscale SiB3 precipitates, formed in-situ. The synthesized samples were characterized using X-ray diffraction and field emission scanning electron microscopy, based on which the enhancement in their thermoelectric and mechanical properties are discussed. Considering the low-cost and non-toxicity of the constituent elements coupled with facile and up-scalable one-step processing employed in its synthesis, Si96B4/SiC nanocomposites could be a potential p-type thermoelectric material for high-temperature power generation applications.
1 March 2018
Synthesis of silver nanowires towards the development the ultrasensitive AgNWs/SiNPLs hybrid photodetector and flexible transparent conductor
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Arvind Kumar, Prajith Karadan, Harish C. Barshilia In this paper, we report the synthesis of silver nanowires (AgNWs) via polyol method towards the fabrication of low cost high sensitive hybrid photodetector. During AgNWs synthesis, NaCl was added to the reaction for controlling the free Ag+ ions concentration during the formation of initial Ag seeds. Field emission scanning electron microscopy results show that AgNWs of diameter ~ 5080nm and length ~ 530m can be achieved. UVVisible absorption spectroscopy and energy dispersive spectroscopy results indicate the formation of AgNWs in highly pure phase. Hybrid detector was fabricated by depositing the AgNWs film on silicon nanopillar (SiNPLs) substrate. Fabricated hybrid AgNWs/SiNPLs photodetector exhibits ~ 10 times more sensitivity as compared to SiNPLs based detector. In addition, AgNWs/SiNPLs detector shows outstanding stability against 20 days exposure to ambient conditions. These results indicate that AgNWs can be utilized to fabricate the high performance one dimensional hybrid photodetectors. The effectiveness of AgNWs to make the transparent flexible devices has also been demonstrated. AgNWs film deposited on a flexible polyethylene terephthalate (PET) substrate revealed a maximum total transmittance and sheet resistance of ~ 94% and ~ 200/sq., respectively.
1 March 2018
Physical and photoelectrochemical properties of the ilmenite NiTiO3 prepared by wet chemical method and its application for O2 evolution under visible light
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): L. Boudjellal, A. Belhadi, R. Brahimi, S. Boumaza, M. Trari The ilmenite NiTiO3 prepared by wet chemical method is characterized by thermal gravimetry (TG), X-ray diffraction (XRD), FTIR and Scanning Electron Microscopy (SEM). The oxide crystallizes in the hexagonal symmetry with grains size in the range [200300nm]. The BET analysis gives a specific surface area of ~ 4m2 g
1 March 2018
First-principles investigation on the structural, elastic, electronic and optical properties and possible mechanism of the photocatalytic properties for orthorhombic and tetragonal KNbO3
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Yong-Qiang Xu, Shao-Yi Wu, Li-Na Wu, Li-Juan Zhang The structural, elastic, electronic, optical and photocatalytic properties are studied for orthorhombic and tetragonal KNbO3 (KNO) based on first-principles methods. The elastic results show that both phases are mechanically stable, and the tetragonal phase exhibits higher hardness and stiffness than the orthorhombic one. The elastic properties also exhibit obvious elastic anisotropy in both crystals. The electronic structures with HSE06 scheme show that both systems are indirect band gap semiconductors, and the Nb-O bonds in tetragonal phase have stronger covalency than those in orthorhombic phase. The optical properties are also calculated with HSE06 method. The complex dielectric function and linear optical properties are discussed in detail. The significant optical anisotropy is observed in (001) direction of tetragonal phase. Then the mechanisms of photocatalytic properties of both polymorphs are further discussed and compared. From the present band structures, the effective mass of photogenerated carriers and optical absorption spectra results, the photocatalytic activity of orthorhombic phase can be higher than the tetragonal one.
1 March 2018
Nickel mono-silicide formation using a photo-thermal process assisted by ultra-violet laser
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Sang Min Jung, Jin Hwan Kim, Chul Jin Park, Moo Whan Shin Photo-thermal processing assisted by laser irradiation is proposed as a novel method to control the phase of nickel silicide with reduction in the diffusion of nickel into the silicon substrate. The third harmonics of Nd3+:Y3Al5O12 laser (wavelength, 355nm) is used for photo-thermal processing. Optical and thermal simulations are performed to obtain an optimum thickness (30nm) of the nickel film for photo-thermal processing and to predict the temperature profile of the nickel-silicon interface during laser irradiation. It is confirmed that Ni2Si, NiSi and NiSi2 phase are effectively formed at the laser energy densities of 15, 2040, and 50mJ/cm2, respectively. We demonstrate that the phases of nickel silicide determined by Raman spectroscopy and X-ray diffraction analyses are in good agreement with those predicted by the heat transfer simulation. In addition, undesirable diffusion of nickel into silicon substrate is considerably reduced by instantaneous photo-thermal processing using the nano-second laser (pulse duration, 6ns).

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1 March 2018
Annealing atmosphere effects on the surface properties of Cd2SnO4 thin films obtained by RF sputtering
Publication date: 1 March 2018
Source:Materials Science in Semiconductor Processing, Volume 75 Author(s): Shengqiang Ren, Tianyu Tang, Yuan Liu, Chuang Li, Lili Wu, Wei Li, Jingquan Zhang, Wenwu Wang, Lianghuan Feng Cd2SnO4 (CTO) thin films were prepared by RF sputtering technique from a CTO target and then annealed under Ar or Ar/CdS atmosphere. The detailed characterizations on the surface properties of as-deposited, Ar-annealed, and Ar/CdS-annealed CTO thin films were carried out by AFM, XPS, UPS, etc. The surface properties of the films are greatly dependent on the annealing atmosphere. Ar/CdS atmosphere promotes the grains to grow but slightly increases the surface roughness. Cadmium atoms sublimated off the CTO thin films during the annealing process and this sublimation can be suppressed under Ar/CdS atmosphere, which causes the surface of CTO thin films not homogeneous as inside. The fundamental band gap is determined to be 2.83eV. The Fermi level position is 1.7eV above the valence band maximum for the as-deposited films, while it shifts to 2.98eV and 3.21eV for the films annealed in Ar and Ar/CdS atmospheres, respectively. Work function for the Ar/CdS-annealed films is about 0.16eV higher than the Ar-annealed ones. These results could be used to design high efficiency thin film solar cells and water photolysis devices, in which the efficiency is sensitive to the surface properties of TCO thin films.

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Nanocrystalline ZnxTe100
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