A novel nano-architecture for ZnO thin films on 〈100〉 Si, GaAs and InP single crystal wafers by L-MBE as value in nano-robotic (machining) device fabrication efforts

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.