Limiting Effect of Interface States Density on Photoelectric Properties of Sol-Gel n-ZnO/p-Si Heterojunction

An n-ZnO/p-Si heterojunction was elaborated using the sol-gel spin-coating technique and simulated by two-dimensional (2D) numerical simulations. The structural, optical, electrical, and photoelectrical properties were investigated. X-ray diffraction (XRD) analysis confirmed the hexagonal wurtzite structure of ZnO. Scanning electron microscopy (SEM) analysis revealed a homogeneous granular structure with mean grain size of 71.42 nm. High optical transmittance and low reflectance in the visible range were measured by ultraviolet-visible (UV-Vis) spectrophotometry. Photoluminescence (PL) measurements revealed the presence of V-O, V-Zn, Zn-i, and O-Zn intrinsic defects. Hall-effect measurements showed a charge carrier density of 1.29 x 10(19) cm(-3), mobility of 1.41 x 10(-2) cm(2) V-1 s(-1) and resistivity of 34.255 2cm in the ZnO layer. Under illumination, the n-ZnO/p-Si structure showed the following photoelectric parameters: J(SC) = 4.62 x 10(-5) A/cm(2), V-oc = 0.385 V, and fill factor (FF) of 31.45%. Finally, simulations using Atlas Silvaco software revealed the existence of an interface states density of around 5 x 10(14) cm(-2), which limits the photoelectric performance of the structure.

Automated summary

In this study, an n-ZnO/p-Si heterojunction was prepared using sol-gel spin-coating technique and analyzed by 2D numerical simulations. The material exhibited characteristics such as hexagonal wurtzite structure, high optical transmittance, and intrinsic defects. Various properties like charge carrier density, mobility, and resistivity were measured, along with photoelectric parameters under illumination. Simulation using Atlas Silvaco software revealed the presence of interface states density that impacts the photoelectric performance of the structure.