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Abstract: A novel highly transparent intrinsic zinc oxide (ZnO) thin films (without adding any dopants and annealing) were grown by pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”- grade ZnO pellets. The effects of substrate temperatures on zinc oxide thin film growth, optical transmission, absorption, reflection and photoluminescence properties were studied. As well as the feasibility of developing high quality transparent oxide thin films was also studied simultaneously. The optical transmission window of such obtained films, i.e., T% (max)⩾95% is broader than those of other transparent conducting oxides such as indium tin oxide (ITO) and absolute rivals that of the most transparent conducting oxides (TCOs). Also as a novelty merit, we want to emphasize as a interesting, significant and novel physical effect that the average optical transmittance of ZnO thin films rivals that of the most transmittive TCO films reported to date for this conductivity level (of the order of 103 Ω−1 cm−1). Also this is the first time that we have applied these PLD prepared ZnO thin films to iso and hetero semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) coatings. From optical studies, we know that the films were act as highly anti-reflective coatings. From photoluminescence study, we confirmed the purity and high electrical conductivity of the deposited thin films of ZnO. The optical parameter values for the films were calculated, tabulated and graphically emphasized. Supplementary studies on surface, electrical, structural and internal morphological properties of zinc oxide thin film growth correlated with optical transmission, absorption, reflection and photoluminescence properties gives added advantages to this work. We hope that surely these data should be helpful either as a scientific or technical basis in the semiconductor processing and technology. [Copyright &y& Elsevier]

Abstract: In this present work, the effects of various substrate temperatures and various substrates on Zinc Oxide (ZnO) thin film growth and on surface morphological properties were studied. To the best of our knowledge this is the first time that laser molecular beam epitaxy (L-MBE), i.e., pulsed laser deposited (PLD) zinc oxide (ZnO) thin films on semiconductor wafers have been applied to Semiconductor–Insulator–Semiconductor (SIS) type multi-junction solar cells, as wide band-gap transparent conducting oxide (TCO) front electrode window layers, compatible with current semiconductor processing techniques. As well as our main aim, the feasibility of developing highly nano-tectured thin films was also studied simultaneously. The surface morphological and film growth characteristics of ZnO thin films laser deposited on to various substrates like glass, Silicon (Si), Gallium Arsenide (GaAs) and Indium Phosphide (InP) at various substrate temperatures like room temperature, 200°C and 300°C using ZnO pallets as targets are very novel, intelligent and significant from reported so for. The deposition process was optimized. The micro- and nano-scale photo-graphs of Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) showed the improvements of crystalline and surface nature of ZnO thin films with respect to various substrate temperatures and substrates. Better surface architecture was observed for thin films deposited at 300°C than RT, 200°C and on InP than Si and GaAs. Increasing the substrate temperature leads the films to fine nano-structure world. The results were discussed in detail. Thus we have developed a novel nano-architecture to obtain high quality ZnO nano-crystalline semiconductor thin films of different nano-scale grain sizes on glass and Si, GaAs and InP semiconductor single crystal wafers by using different substrate temperatures and substrates as controlling tools as value in practical nano-robotic (machining) device fabrication efforts. [Copyright &y& Elsevier]

Intrinsic epitaxial zinc oxide (epi-ZnO) thin films were grown by laser-molecular beam epitaxy (L-MBE), i.e., pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”-grade ZnO pellets. The effects of substrate temperatures on ZnO thin film growth, electrical conductivity (σ), mobility (μ) and carrier concentration (n) were studied. As well as the feasibility of developing high quality conducting oxide thin films was also studied simultaneously. The highest conductivity was found for optimized epi-ZnO thin films is σ=0.06×103 ohm-1 cm-1 (n-type) (which is almost at the edge of semiconductivity range), carrier density n=0.316×1019 cm-3 and mobility μ=98 cm2/V s. The electrical studies further confirmed the semiconductor characteristics of epi-n-ZnO thin films. The relationship between the optical and electrical properties were also graphically enumerated. The electrical parameter values for the films were calculated, graphically enumerated and tabulated. As a novelty point of view, we have concluded that without doping and annealing, we have obtained optimum electrical conductivity with high optical transparency (⩾95%) for as deposited ZnO thin films using PLD. Also, this is the first time that we have applied PLD made ZnO thin films to iso-, hetero-semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) window layer. We hope that surely these data be helpful either as a scientific or technical basis in the semiconductor processing. [Copyright &y& Elsevier]

High quality epitaxial indium zinc oxide (heavily indium oxide doped) (epi-n-IZO) thin films were optimized by laser-molecular beam epitaxy (L-MBE) i.e., pulsed laser deposition (PLD) technique for fabricating novel iso- and hetero-semiconductor–insulator–semiconductor (SIS) type solar cells using Johnson Matthey “specpure”- grade 90% In2O3 mixed 10% ZnO (as commercial indium tin oxide (ITO) composition) pellets. The effects of substrate temperatures, substrates and heavy indium oxide incorporation on IZO thin film growth, opto-electronic properties with 〈1 0 0〉 silicon (Si), gallium arsenide (GaAs) and indium phosphide (InP) wafers were studied. As well as the feasibility of developing some novel models of iso- and hetero-SIS type solar cells using epi-IZO thin films as transparent conducting oxides (TCOs) and 〈1 0 0〉 oriented Si, GaAs and InP wafers as base substrates was also studied simultaneously. The optimized films were highly oriented, uniform, single crystalline approachment, nano-crystalline, anti-reflective (AR) and epitaxially lattice matched with 〈1 0 0〉 Si, GaAs and InP wafers without any buffer layers. The optical transmission T (max) ⩾ 95% is broader and absolute rivals that of other TCOs such as ITO. The highest conductivity observed is σ=0.47×103 Ω-1 cm-1 (n-type), carrier density n=0.168×1020 cm-3 and mobility μ=123 cm2/V s. From opto-electronic characterizations, the solar cell characteristics and feasibilities of fabricating respective epi-n-TCO/〈1 0 0〉 wafer SIS type solar cells were confirmed. Also, the essential parameters of these cells were calculated and tabulated. We hope that these data be helpful either as a scientific or technical basis in semiconductor processing. [Copyright &y& Elsevier]

We have optimised and deposited epitaxial indium zinc oxide (epi-IZO) (In2Zn2O5) thin films on 〈1 0 0〉 oriented Si, GaAs and InP by laser-molecular beam epitaxy (L-MBE) technique, i.e., pulsed laser deposition (PLD). Optimised growth conditions have been obtained for the deposition of high quality epi-IZO thin films. To our knowledge, this is the first time that the PLD deposited indium zinc oxide thin films on semiconductor wafers have been applied to semiconductor–insulator–semiconductor (SIS) iso- and hetero-type junction solar cell structures as wide band gap transparent conducting front electrode-window layers. We have carried out X-ray diffraction (XRD) and energy dispersive chemical analysis (EDAX) to determine the Structural and compositional properties of as-grown thin films. The crystalline quality of the obtained thin films is similar to that of the bulk single crystals. Increasing the deposition temperature leads the thin films to fine nano-structure nature. In the present work, the effects of various substrate temperatures, substrates and heavy indium oxide doping on indium zinc oxide thin film growth, structural and compositional properties were analysed. As well as our main aim, the feasibility of developing high quality transparent conducting oxide (TCO) thin films for opto-electronic devices was also studied simultaneously. Our novel achievement in this work is without any buffer layers, we have obtained good epitaxial lattice matching between the highly oriented IZO functional layers and the substrate materials suitable for III–V based high-speed opto-electronic and micro-electronic devices. [Copyright &y& Elsevier]

Highly textured zinc oxide (ZnO) thin films have been optimized and deposited by pulsed laser deposition (PLD), i.e., laser-molecular beam epitaxy technique on 〈100〉 Si, GaAs and InP wafers compatible with current semiconductor processing techniques. To our knowledge this is the first time that the PLD deposited zinc oxide thin films on semiconductor wafers have been applied to semiconductor–insulator–semiconductor type multi junction (homo and hetero) solar cell structures as wide band gap transparent conducting oxide (TCO) front electrode-emitter layers. In this present work, the effects of various substrate temperatures and substrates on ZnO thin film growth, structural and compositional properties were analyzed and the feasibility of developing high-quality TCO thin films for opto-electronic devices was also studied simultaneously. Increasing the deposition temperature leads the thin films to fine nano-structures. Our achievement in this work is elimination of any buffer layer like GaN and we have obtained good epitaxial lattice matching between the ZnO functional layers and the 〈100〉 substrates suitable for III–V-based high-speed opto- and micro-electronic devices. [Copyright &y& Elsevier]