Effect of Sn doping on optical and electrical properties of CuO thin films deposited by spray pyrolysis technique

Abstract

The aim of this work is the study of the effect of tin (Sn) doping and annealing on the optical and electrical properties of copper oxide (CuO) thin films deposited by ultrasonic spray pyrolysis technique to obtain good photoelectric properties it an important candidate in many technological applications. In this work, we have prepared these films onto glass substrates with different Sn concentrations from 0 to 12 at. % in the aqueous solution of copper (II) chloride dihydrate and tin (II) chloride dihydrate as precursors. Substrate temperature, solution concentration, nozzle-substrate distance, and the deposition time were kept constant during the whole deposition process. These films were characterized, before and after annealing, using the UV-Visible-NIR Spectrophotometer and the four-point method to determine their optical and electrical properties. All samples obtained have good physical properties that varied with the doping percentage and the annealing. It should be noted that increasing Sn doping in CuO films leads to an increase in thickness and optical band gap, while the refractive index, optical transmittance, Urbach energy, and electrical conductivity decrease. On the other hand, annealing reduces the thickness, band gap, Urbach energy, and optical transmittance, while increasing the refractive index and electrical conductivity.