Influence of Ag+ ions on the physical properties of spray coated CeO2 thin films and photo-response of p-Si/n-SDC junction diodes

Two-layer optoelectronic devices like p-n junction diode have attracted much attention due to their modern fast switching, optical detection, and sensing applications. In this work, we have fabricated a p-Si/n-SDC junction diode with higher photocurrent by preparing pure and Silver doped CeO2 (SDC) thin-film through facile spray pyrolysis. A monophase cubic fluorite crystal structure was confirmed by XRD analysis. FE-SEM micrographs showed noticeable grain growth after doping the Silver (Ag) in CeO2 film. UV-Vis. study revealed a sharp absorption peak at 340 nm for 6 wt. % of SDC film. The conductivity of SDC films was found to improve while increasing the doping level of Ag. The p-Si/n-SDC junction diode exhibited a higher photocurrent under an illumination environment, conforming to the fabricated diode's photo-conducting behavior. Compared with the p-Si/n-CeO2 diode, the SDC diode recorded a higher ON-OFF response as expected.