Enhancing current spreading performance of GaN-based ultraviolet light-emitting diode chips through periodic doping composite barrier structures

Abstract

In response to the issue of current crowding in GaN-based ultraviolet (UV) light-emitting diode (LED) chips, a periodic doping composite barrier structure is proposed. The results of the optical intensity distribution demonstrate that the device with the periodic doping composite barrier structure exhibits a more uniform light distribution compared to the device with traditional structures. Moreover, when the injected current is 20 mA, the light output power (LOP) and wall-plug efficiency (WPE) are improved by 11.99% and 13.5%, respectively. Experimental and simulation results indicate that the periodic doping composite barrier structure enhances the current spreading performance through two mechanisms: (1) the introduction of an electron barrier layer enhances lateral current transport; (2) increase the ratio of longitudinal to transverse resistivity of the material to further enhances current spreading performance.

Keywords:

• GaN
• ultraviolet
• light-emitting diodes
• current crowding

Additional information

Funding

This research was funded by the National Key R&D Program of China (Grant No. 2016YFB0400800), the National Natural Science Foundation of China (Grant No. 61634005), and the Key R&D projects of Shaanxi Province (Grant Nos. 2018ZDCXL-GY-01-07 and 2018ZDCXL-GY-01-02-02).