Synthesis of Zn Doped Copper Iodide Film Characteristics by Thermal Evaporation System

Abstract

Copper iodide (CuI) thin films have garnered significant attention due to their wide bandgap, high hole mobility, and excellent transparency, making them promising candidates for optoelectronic and photovoltaic applications. Doping CuI with zinc (Zn) introduces a pathway for enhancing its structural, optical, and electrical properties. In this study, Zn-doped CuI thin films were synthesized using a cost-effective and scalable deposition technique like horizontal thermal evaporation (TE) technique. The structural analysis revealed a preserved zincblende crystal structure of CuI, with Zn incorporation leading to shift in (111) XRD peak. Atomic force microscopy (AFM) was used to measure the surface roughness of CuI thin films at various Zn²⁺ doping levels. Hall effect measurements revealed that excessive Zn doping could transition the films from p-type to n-type conductivity. Optimal Zn doping, identified as 1 mol% Zn²⁺, significantly enhanced the quality of the CuI thin films, resulting in improved photoresponse performance as demonstrated by I-V measurements. Electrical measurements demonstrated enhanced p-type conductivity, resulting from the Zn dopant's influence on carrier concentration and mobility. These results highlight the potential of Zn-doped CuI thin films for advanced optoelectronic devices, particularly as the UV photodetectors.