Effects of ageing on the electrical characteristics of Cd/CdS/ n-Si/Au–Sb structure deposited by SILAR method

Abstract

Cd/CdS/ n-Si/Au–Sb structure has been fabricated by the Successive Ionic Layer Adsorption and Reaction (SILAR) method and the influence of the time dependent or ageing on the characteristic parameters are examined. The current–voltage ( I– V), capacitance–voltage ( C– V) and capacitance–frequency ( C– f) characteristics of the structure have been measured immediately, 1, 3, 5, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150 and 165 days after fabrication of the structure. The characteristic parameters of the structure such as barrier height, ideality factor, series resistance are calculated from the I– V measurements and the barrier height, carrier concentration values are calculated from reverse bias C − 2 – V measurements at 500 kHz and room temperature. Furthermore, the density distribution and time constant of the interface states have been calculated from the C– f measurements using the Schottky Capacitance Spectroscopy method as a function of ageing time. It has been seen that the changes of characteristic parameters such as barrier height, ideality factor and series resistance of Cd/CdS/ n-Si/Au–Sb structure have lightly changed with increasing ageing time. At the same time, the rectifying ratio of the device increases with ageing time. It can be clearly said that the I– V characteristics of device get better with time.