Study of barrier inhomogeneities in I–V-T and C-V-T characteristics of Al/Al2O3/PVA:n-ZnSe metal–oxide–semiconductor diode

Abstract

This paper presents detailed analysis of forward and reverse bias I-V and C-V characteristics of Al/Al2O3/PVA:n-ZnSe metal-oxide-semiconductor diode. PVA:n-ZnSe nanocomposites are prepared by chemical bath deposition technique. The alumina layer is deposited on Al substrate by electrolytic anodization method. The temperature dependence I-V parameters such as series resistance (RS), the ideality factor (n), the barrier height (φb), the Richardson constant (A*), mean barrier height, and the leakage current (Ileakage) have been explained on the basis of inhomogeneity. The series resistance obtained from Chenug’s method and Norde’s method shows close agreement with each other. In C-V measurements, in the reverse bias of Al/Al2O3/PVA:n-ZnSe metal-oxide-semiconductor diode has been performed as a function of temperature. The temperature dependence C-V parameters barrier height φ(C−V), the built-in-voltage (Vbi), carrier concentration (ND), Fermi energy (EF), and depletion layer width (W) have been calculated at different temperatures. The discrepancy in barrier height obtained from I-V and C-V measurements and barrier inhomogeneities of Al/Al2O3/PVA:n-ZnSe contact has been explained by assuming Gaussian distribution of barrier heights using potential fluctuation model.