Backward-Diode Heterostructure Based on a Zinc-Oxide Nanoarray Formed by Pulsed Electrodeposition and a Cooper-Iodide Film Grown by the SILAR Method

Abstract

A heterostructure promising for designing a backward diode is formed from a zinc-oxide nanorod array and a nanostructured copper-iodide film. The effect of modes of successive ionic layer adsorption and reaction (SILAR) deposition and the subsequent iodization of CuI films on smooth glass, mica, and fluorine-doped tin oxide (FTO) substrates and on the surface of electrodeposited nanostructured zinc-oxide arrays on the film structure and electrical and optical properties is investigated. A connection between the observed variations in the structure and properties of this material and intrinsic and iodination-induced point defects is established. It is found that the cause and condition for creating a backward-diode heterostructure based on a zinc-oxide nanoarray formed by pulsed electrodeposition and a copper-iodide film grown by the SILAR method is the formation of a p⁺-CuI degenerate semiconductor by the excessive iodination of layers of this nanostructured material through its developed surface. The n-ZnO/p⁺-CuI barrier heterostructure, which is fabricated for the first time, has the I–V characteristic of a backward diode, the curvature factor of which (γ = 12 V^–1) confirms its high Q factor.