Investigations on structural, morphological and UV light detection characteristics in p-ZrO2/ n-Si Heterostructure based devices

The development of hetero-structured based UV photodiode is a rapidly growing interest in the area of optoelectronic applications. In recent years, one of the next generation semiconductor material zirconium dioxide (ZrO2), has attracted much attention for UV photodiode applications. The curent research work focuses on the fabrication of ultraviolet (UV) photodetectors using ZrO2 nanocrystals with different molar concentrations. Using the co-precipitation method, ZrO2 nanocrystals were formed onto n-Si substrate. The prepared ZrO2 nanocrystals were characterized by XRD, UV-visible spectroscopy, FeSEM, HRTEM, PL spectroscopic analysis. The structural analysis of ZrO2 nanoparticles shows the cubic space groups with ((Fm-3m, Z = 4) and (Im-3m, Z = 1) respectively. The morphological analysis reveals the irregular shape and highly agglomerated. The TEM and HRTEM images, and SAED pattern of ZrO2 NPs were obtained at higher mole concentration. The optical energy band gap of ZrO2 nanocrystals were determined in between 3.12 and 2.86 eV. The PL emission spectrum of ZrO2 nanoparticles shows highly intensive emission bands between 360 nm and 520 nm. The optimum ZrO2 (0.3 M) nanocrystal layers were formed onto n-Si substrate which was stacked between top and bottom Ag electrodes. The current-voltage measurements (I-V) plots and ln J-V plots characteristics of the fabricated Ag/p-ZrO2/n-Si/ Ag devices were investigated under dark and UV illumination. The p-ZrO2/n-Si junction diodes exhibit the ideal rectifying function at higher molar concentration of ZrO2 diode, and the reverse saturation with maximum photo sensitivity was investigated.