Investigated the Current Spreading and Thermal Effect on Nitride-based Light Emitting Diodes by Surface Thermal Images Analysis

DOI: 10.5176/2301-3516_OPAP13.16

Authors: C. K. Wang, Y. Z. Chiou, J. Lee, J. J. Tang, W. S. Chen, C. M. Cheng, and D. H. Lee, T. H. Chiang, S. J. Chang, and S. P. Chang, K. H. Chen

Abstract:

In this study, the nitride-based light emitting diodes (LEDs) with different current blocking layer (CBL) width were used to elucidate the relationship between effective injection current density and external quantum efficiency (EQE). We suggested that the EQE is related with current spreading ability. The results indicate that the reduction of efficiency droop on the LED with wide CBL region at higher current density due to superior current spreading. Better current spreading can not only increase the effective emitting area but also improve the effective injection current density. Besides, the operated temperature of the LED with wide CBL region was lower than others due to the reduction in current crowding effect.

Keywords: GaN, LED, EQE, current spreading