Enhanced Optoelectronic Performance of Yellow Light-Emitting Diodes Grown on InGaN/GaN Pre-Well Structure

Nanomaterials

Xiaoyu Zhao¹  Liyan Gong¹  Shengjun Zhou¹  Zehong Wan²  Guoyi Tao² 

[1] Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China;The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China;

关键词: gallium nitride;    yellow LED;    pre-well structure;    optoelectronic device;   

DOI  :  10.3390/nano11123231

来源: DOAJ

【 摘 要 】

InGaN-based long-wavelength light-emitting diodes (LEDs) are indispensable components for the next-generation solid-state lighting industry. In this work, we introduce additional InGaN/GaN pre-wells in LED structure and investigate the influence on optoelectronic properties of yellow (~575 nm) LEDs. It is found that yellow LED with pre-wells exhibits a smaller blue shift, and a 2.2-fold increase in light output power and stronger photoluminescence (PL) intensity compared to yellow LED without pre-wells. The underlying mechanism is revealed by using Raman spectra, temperature-dependent PL, and X-ray diffraction. Benefiting from the pre-well structure, in-plane compressive stress is reduced, which effectively suppresses the quantum confined stark effect. Furthermore, the increased quantum efficiency is also related to deeper localized states with reduced non-radiative centers forming in multiple quantum wells grown on pre-wells. Our work demonstrates a comprehensive understanding of a pre-well structure for obtaining efficient LEDs towards long wavelengths.

【 授权许可】

Unknown