InGaN multiquantum well structure with a reduced internal electric field and carrier decay process by tunneling

Abstract

An InGaN/InGaN multiquantum well (MQW) structure with a reduced internal electric field is grown, and compared with a conventional InGaN/GaN MQW structure. Time-integrated and time-resolved photoluminescence (PL) are measured as a function of an external bias voltage. The flatband condition, in which the external bias voltage completely compensates the internal electric field, is found by a measurement of PL peak energy as a function of bias voltage. From the measurement of the integrated PL intensity and the PL lifetime, we observe that tunneling has an important role in the carrier decay process of the biased MQW structure. Using the flatband condition, the internal electric field is calculated to be 1.75 and 2.15 MV/cm for InGaN/InGaN and InGaN/GaN structures, respectively.