Polarization effect on electronic band structure of InGaN/GaN multi-quantum wells

Abstract

We have characterized the effect of piezoelectric field in strained InGaN/GaN multi-quantum wells (MQWs) by using the deep level transient spectroscopy (DLTS). The photoluminescence peak of the quantum wells was observed at 2.612 eV roughly matched with DLTS results. And the carrier profile obtained by the relation of capacitance-voltage showed carrier accumulation peaks representing the quantum wells. The thermal activation energy calculated from DLTS spectra decreased by about 0.12 eV with increasing the reverse bias field. This energy shift can be explained by the partial compensation of the internal piezoelectric field. In this report, we suggested the DLTS technique as a useful method to characterize the quantum confined Stark effect in InGaN/GaN MQWs structure.