Effect of Cu doping on the electrical Properties of ZnTe by Vacuum Thermal Evaporation

Abstract

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10^-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (E_a1, E_a2), expect 3% Cu. The activation energy (E_a1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×10²⁰ m^-3) , Hall mobility (0.464m²/V.s) for pure ZnTe film, increases the carrier concentration (6.3×10²¹m^-3) Hall mobility (2m²/V.s) for doping (Cu at 3%) film, but  decreases by increasing Cu concentration.