Blue InGaN/GaN multiple quantum well light-emitting diodes with the conventional and graded last barriers (GLB) are numerically investigated. When the last GaN barrier is replaced by a linearly graded InxGa1 − xN barrier with increasing indium composition in the growth direction, the forward voltage is reduced from 3.60 V to 3.25 V, and the efficiency droop is improved from 36% to 13%. Simulation results indicate that these improvements can be attributed to the formation of a deep potential well in the GLB which enhances the electron confinement and improves the hole injection efficiency.
Droop improvement in blue InGaN/GaN multiple quantum well light-emitting diodes with indium graded last barrier
Chang Sheng Xia, Z. M. Simon Li, Wei Lu, Zhi Hua Zhang, Yang Sheng, Li Wen Cheng; Droop improvement in blue InGaN/GaN multiple quantum well light-emitting diodes with indium graded last barrier. Appl. Phys. Lett. 5 December 2011; 99 (23): 233501. https://doi.org/10.1063/1.3665252
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