Title :
An Improved Ohmic Contact to n-Type N-Face GaN for Extremely Low Voltage-Operated Vertical Light Emitting Diodes
Author :
Wang, Liancheng ; Guo, Enqing ; Liu, Zhiqiang ; Yi, Xiaoyan ; Wang, Guohong
Author_Institution :
Lighting R&D Center, Chinese Acad. of Sci., Beijing, China
Abstract :
Low resistance and thermally stable n-type contact to N-polar GaN is essentially important for vertical light emitting diodes (VLEDs) . In this paper, the difference of the contacts deposited on wet-etching roughed and un-roughed surface was investigated. It was found that VLEDs with contacts deposited on roughed surface exhibits lower leakage currents yet higher operating voltage. Based on this, a new scheme for depositing metallization contacts has been developed. VLEDs fabricated based on this scheme shows extremely low operating voltage (2.75V@350mA), low reverse leakage current (0.015μA@-5V). There is no optical output compromise and aging test further confirmed its stability.
Keywords :
III-V semiconductors; electrical resistivity; etching; gallium compounds; leakage currents; light emitting diodes; metallisation; ohmic contacts; surface roughness; thermal stability; wide band gap semiconductors; GaN; current 350 mA; electrical resistance; low voltage-operated vertical light emitting diodes; metallization contacts; ohmic contact; operating voltage; reverse leakage current; thermally stable n-type N-face contact; voltage 2.75 V; voltage 5 V; wet-etching roughed surface; wet-etching unroughed surface; Conductivity; Contacts; Gallium nitride; Rough surfaces; Surface morphology; Surface roughness; Surface treatment;
Conference_Titel :
Photonics and Optoelectronics (SOPO), 2011 Symposium on
Conference_Location :
Wuhan
Print_ISBN :
978-1-4244-6555-2
DOI :
10.1109/SOPO.2011.5780596
