Current transport and capacitance-voltage characteristics of n-InSb/p-GaP prepared by flash evaporation and liquid phase epitaxy

摘要

In this paper, n-Type of InSb films were successfully fabricated on p-GaP monocrystalline substrates by both flash evaporation technique and liquid phase epitaxy to study some features of current transport in strained heterojunctions. The elemental composition of the prepared films was confirmed by energy dispersive X-ray (EDX) spectroscopy. The morphology of the films was characterized by scanning electron microscopy (SEM). The electrical properties of the n-InSb/p-GaP junctions prepared by flash evaporation and liquid phase epitaxy were investigated through capacitance-voltage and current-voltage measurements, performed under dark condition in the temperature range 300–400 K. Due to misfit dislocations, the interface showed rectifying behavior. At low voltages, current in the forward direction was found to obey the diode equation and the conduction was controlled by a thermionic emission mechanism. For relatively higher voltages, conduction was dominated by a space-charge-limited conduction mechanism with single trap level. This is evidence of a depletion of the space charge region due to Fermi level pinning by surface states at the InSb/GaP interface. Junction parameters of the n-InSb/p-GaP like ideality factor and barrier height were obtained and variations were monitored as a function of temperatures. Also, an attempt to explore the governing current flow mechanism was made.