Impact of Substrate Temperature on the Properties of Rare-Earth Cerium Oxide Thin Films and Electrical Performance of p-Si/n-CeO2 Junction Diode

In this work, we report a p-Si/n-CeO(2)junction diode fabricated by a cost-effective and large-area deposition technique of jet nebulizer spray pyrolysis. The n-CeO(2)layer was coated on four different substrate temperatures (T-sub) 350, 400, 450, 500 degrees C and their properties were studied by various techniques like XRD, FE-SEM with EDX, UV-Vis and I-V characterization. XRD pattern confirmed a cubic fluorite crystalline phase of CeO(2)thin films with preferential growth along (2 0 0) direction. A smooth surface with inter-connected smaller grains was recorded by FE-SEM micrographs and also the existing elements Ce and O have been confirmed. For T(sub )of 450 degrees C, an exceptional optical absorption with smaller band energy of 3.3 eV was recorded in the UV-Vis spectrum. The electrical conductivity results indicated that all the films are semiconducting in nature. I-V characteristics of all the fabricated diode showed better rectification in dark with excellent photovoltaic characteristics under light exposed condition. The photosensitvity of the diode varied from 21.94 to 1093.75% with substrate temperature. Our results strongly suggested that rare-earth based p-Si/n-CeO(2)diodes are suitable for future applications in ultraviolet photo-detector and photo-diode.