Structural and electrical characteristics of n-InSb/p-GaAs heterojunction prepared by liquid phase epitaxy

Abstract

Thin films of n-InSb were successfully fabricated on p-GaAs single crystalline substrates by liquid phase epitaxy, LPE. The elemental composition of the prepared films was confirmed by energy dispersive X-ray (EDX) spectroscopy. The morphology and crystal structure of the film were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The electrical characteristics of liquid phase epitaxially grown n-InSb thin films on GaAs single crystal were investigated. The current density–voltage (J–V) characteristics of n-InSb/p-GaAs heterojunction diode in dark condition were measured at different temperatures in the temperature range 300–400K. The device exhibited a rectifying property. The current in the prepared heterojunction was found to obey the thermionic emission model in the voltage range (V<0.4V) while in the voltage range (0.4<V<1.5) the current is space charge limited dominated by single trap distribution. The current density–voltage characteristics allow us to evaluate some characteristic parameters such as the series resistance, Rs, shunt resistance, Rsh, ideality factor, n, and the barrier height, Φb. The variation of 1/C2 with voltage shows a straight line at high frequency indicating the formation of barrier between InSb and GaAs and other important parameters were calculated.