A Theoretical Study of Transport Property of Heterojunction and Evaluation of Electric Fields of The Space Charge Region and Energy Band of The Heterojunction Under Applied Bias Voltage

Abstract

This paper presents a theoretical study of transport property of heterojunction and evaluation of electric fields of the Space charge region and energy band of the heterojunction under applied bias voltage. The study exhibits a typical XRD pattern of a 500 thick LSMO film growing directly on the Si (001) substrate. The plane lattice parameter is about 5.43 A  for Si. and about 3.86 A   for LSMO. With the LSMO unit cell rotating 45 around the S surface normal (100) axis, the lattice mismatch between LSMO and Si is about 0.55 %. The small lattice mismatch allows a nearly epitaxial growth of LSMO on Si substrate. The study presents the experimental and theoretical results of I-V curves of the LSMO/Si heterostructure over the temperature range of 250-300 K. The solid, dashed, dotted lines represent the theoretical current-voltage characteristics at the temperature of 300 K, 275 K and 250 K respectively and the  experimental data obtained at 300 K. 275 K and 250 K are denoted by solid squares, solid stars and solid triangles respectively The exponential data clearly present asymmetric f-V curves of the LSMO/Si heterojunction The theoretical calculation results show the currents increased rapidly with the increasing forward-bias voltages, which was in good agreement with the experimental data in the forward-bias case. The diversion between the calculation results and experimental results in the reverse-bias case is mainly due to the neglect of the leakage current and the tunneling current in the calculation.