A Facile Fabrication, Microstructural, Optical, Photoluminescence and Electrical Properties of Ni@CeO2 Films and p-Si/n-NDC Diodes for Photodetection Application

Pure CeO2 and Ni-doped cerium oxide (NDC) films were deposited by a facile and economic jet nebulizer spray pyrolysis (JNSP) process at 450 oC substrate temperature. Here, efforts have been done to enhance the performance of the NDC diode using various doping concentrations of Ni (0, 2, 4, and 6 wt%). X-ray diffraction revealed polycrystalline film formation with a cubic crystal structure and the crystallite size of CeO2 was increased from 10 to 21 nm on Ni doping. EDX study confirms the presence of Ni in NDC films. FESEM explicitly shows fine spherical grains-like morphology. The optical studies indicate the reduction in the bandgap of CeO2 from 3.30 to 2.86 eV on Ni doping. The Photoluminescence (PL) spectrum proves that the oxygen vacancy is created in the CeO2 thin films while doping with Ni which leads to the blue shift and intensity enhancement of emission peak. NDC film prepared with 6 wt% showed a higher electrical conductivity ~ 3.76 × 10–10 S/cm which indicates that it is suitable for photodiode fabrication. The fabricated p-Si/n-NDC photodiode works with superior parameters like ideality factor (n) and barrier height (ΦB) under dark and illuminated conditions. The saturation current (Io) of the p-Si/n-NDC diode is varied from ~ 2.69 × 10–05 to 6.57 × 10–04 A with Ni concentrations. The estimated n and ΦB values of the p-Si/n-NDC junction diode are found to be decreased from 7.6 to 2.5 and 0.72 to 0.60 eV. These outcomes indicate that the fabricated photodiode is a useful element in optoelectronic devices.