Study of Thermoelectric and Optical Characteristics of Zn Doped Cu2O Thin Films

Abstract

Cuprous Oxide (Cu2O) based semiconductor materials have lately attracted attention for their electrical and optical properties owing to its potential usage in cutting-edge electronics and solar cells. The current research is focused on thermoelectric and optical properties of Zinc (Zn) doped Cu2O. Thin films of pure and Zn doped Cu2O were deposited by spin coating technique and optical properties were examined via ellipsometry. To cross check the parameters, the simulation studies were also done. The density functional theory calculations were used to model Zinc (Zn) incorporated Cu2O crystals and predict their thermoelectric and optical responses. All the simulations were performed using an extended gradient approximation method, with the full-potential linearized augmented plane wave technique taken into account. Solutions were prepared by Sol gel route and then Spin coating technique was used to create Cu2O thin films with a consistent morphology that were either pure or included Zn at concentrations of 3.125, 6.25, and 12.5 wt.%. There is a strong relationship found between electrical, optical, and thermoelectric characteristics, by both ab-initio and experimental studies. The experimental results were in well agreement with simulation results. With the addition of Zn to the Cu2O structure, a reduction in the band gap was observed and an optical band gap of 1.9eV was recorded for 12.5 wt.% Zn doped Cu2O but in undoped Cu2O a higher optical band gap of 2.2eV was observed. In the visible range, the absorption coefficient and real epsilon show a dramatic increase with Zn doping. Doped samples also showed higher values of Seebeck coefficient for a wide temperature range as compared to the undoped samples. Due to their unique properties, the results suggest that these materials might be used in a variety of optoelectronic and dielectric devices