Title :
Lateral Current Spreading Effect on the Efficiency Droop in GaN Based Light-Emitting Diodes
Author :
Shanjin Huang ; Bingfeng Fan ; Zimin Chen ; Zhiyuan Zheng ; Hongtai Luo ; Zhisheng Wu ; Gang Wang ; Hao Jiang
Author_Institution :
State Key Lab. of Optoelectron. Mater. & Technol., Sun Yat-sen Univ., Guangzhou, China
Abstract :
The lateral current spreading (CS) effect on the efficiency droop in GaN-based LEDs has been studied in terms of the CS distance (LCS) using a designed pattern with the 2-D current spreading profile. The correlations of CS effect with the electrical, luminescent and electric-thermal properties of the LEDs have been discussed. LEDs with the LCS longer than the theoretically calculated effective CS length (Leff) suffer from more serious efficiency droop and the degradation of luminescent properties. However, the influence of CS effect on the ideality factors of LEDs is not obvious. Higher chip temperature caused by poor CS was observed and may further enlarge the efficiency droop.
Keywords :
III-V semiconductors; gallium compounds; light emitting diodes; thermal properties; wide band gap semiconductors; 2D current spreading profile; CS distance; CS length; GaN; efficiency droop; electric-thermal properties; lateral current spreading effect; light-emitting diode; luminescent properties; Current density; Gallium nitride; Light emitting diodes; Proximity effects; Semiconductor device measurement; Solid state lighting; Temperature measurement; Efficiency droop; ideality factor; lateral current spreading; light-emitting diodes (LEDs);
Journal_Title :
Display Technology, Journal of
DOI :
10.1109/JDT.2012.2225092
