Ac conductivity and dielectric spectroscopy studies on tin oxide thin films formed by spray deposition technique

Au/tin oxide/n-Si (1 0 0) structure has been created by forming a tin oxide (SnO2) on n-type Si by using the spray deposition technique. The ac electrical conductivity (σac)(σac) and dielectric properties of the structure have been investigated between 30 kHz and 1 MHz at room temperature. The values of ε'ε', ε″ε″, tanδ, σacσac, M'M' and M″M″ were determined as 1.404, 0.357, 0.253, 1.99×10−7 S/cm, 0.665 and 0.168 for 1 MHz and 6.377, 6.411, 1.005, 1.07×10−7 S/cm, 0.077 and 0.078 for 30 kHz at zero bias, respectively. These changes were attributed to variation of the charge carriers from the interface traps located between semiconductor and metal in the band gap. It is concluded that the values of the ε'ε', ε″ε″ and tanδ increase with decreasing frequency while a decrease is seen in σacσac and the real (M')(M') and imaginary (M″)(M″) components of the electrical modulus. The M″M″ parameter of the structure has a relaxation peak as a function of frequency for each examined voltage. The relaxation time of M″M″(τM″)(τM″) varies from 0.053 ns to 0.018 ns with increasing voltage. The variation of Cole–Cole plots of the sample shows that there is one relaxation.