Fabrication of transparent p-CuI/n-ZnO heterojunctions using solution-processed spin coating technique

Abstract

Semiconductor heterostructures are considered as the building block of advanced semiconductor devices. Here we report the fabrication of p-CuI/n-ZnO heterojunction using the solution-processed spin-coating technique. The structural, morphological and optical properties of the synthesised CuI nanostructures, CuI and ZnO thin films were studied using XRD, FESEM and UV–Visible spectroscopy. XRD studies confirm the formation of zinc blende γ-CuI nanostructures. The CuI thin films without any impurity phases were deposited and the band gap was found to be in the range of 2.86–2.95 eV. The ZnO thin films were grown by spin coating show hexagonal wurtzite structure from the XRD studies. The optical band gap of the ZnO thin films was obtained to be 3.27 eV. The J-V measurement of the p-CuI/n-ZnO heterojunction confirms the rectifying behaviour. A variation in the ideality factor at different voltage ranges is identified, attributed to the dominance of diffusion and recombination current.