Electrical and Interfacial Properties of an Antipyrine Derivative/p-Si Heterojunction

Abstract

Electrical properties of a Au/N-(5-{cyano-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-hydrazono]-methyl}-[1,3,4]thiadiazol-2-yl)-benzamide (ACTB)/p-Si/Al heterojunction have been investigated by using current-voltage (I-V) and capacitance-voltage (C-V) measurements. At forward voltages V≤0.36 volt, thermionic emission theory was used to determine the ideality factor and zero-bias barrier height of the device. Although, the device is found to be nonideal in showing an ideality factor of 1.84, it is found to have a modified barrier height value (0.71 eV) compared to a conventional Au/p-Si contact. Cheung functions were used to obtain the barrier height, series resistance and ideality factor of the diode. The current is found to be controlled by the space charge limited current (SCLC) dominated by exponential trap distribution in the voltage range 0.36<V≤1.56 and SCLC dominated by a single trap in the voltage range 1.56<V ≤2. The I-V characteristics in the reverse direction are analyzed in terms of Poole–Frenkel and Schottky mechanisms. C-V characteristics show that the junction is of an abrupt nature in which the built-in potential, barrier height and charge carrier concentration are estimated. Based on combined I-V and C-V characteristics, the interface state density of the heterojunction has also been calculated. The ACTB film can be used in the device modification applications of the conventional Au/p-Si diodes.