Demonstration of Weak Polarization Electric Field III-N LEDs based on Polar Plane

Abstract

A strong polarization electric field (PEF) in III-nitride semiconductors has adverse effects on the performance of III-N light-emitting diodes (LEDs). However, to reduce the PEF of III-N LEDs based on the polar plane (c-plane) remains a big challenge. Here, a weak PEF blue LED on c-plane GaN with an InGaN/AlGaN superlattices (SLs) quantum barrier and InGaN quantum well grown by metal-organic chemical vapor deposition is proposed. The InGaN/SLs multiple quantum wells (MQWs) show a significant reduction of PEF compared with traditional InGaN/GaN MQWs. A low electric field of 0.5 MV cm−1 is obtained, which is confirmed by power-dependent photoluminescence (PL) and time-resolved PL measurements. The proposed LEDs with InGaN/AlGaN SLs barriers present a low efficiency droop, a great wavelength stability, and a high −3 dB E-O modulation bandwidth up to 1.01 GHz. This work demonstrates the role of InGaN/AlGaN SLs barriers in reducing the PEF of III-N LEDs and provides a feasible technical route to achieve the weak PEF LEDs on c-plane, which can be expanded and applied to the preparation of high-performance, long wavelength, and deep UV III-N LEDs.