Advantages of blue InGaN light-emitting diodes without an electron-blocking layer by using AlGaN step-like barriers
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With the purpose to increase the uniformity of carrier distribution without sacrificing the enhancement of carrier injection efficiency, the light-emitting diodes (LEDs) without an electron-blocking layer (EBL) by using AlGaN step-like barriers (SLBs) is proposed and investigated numerically. The simulation results show that the enhanced electron confinement and hole injection efficiency are mainly attributed to the mitigated downward band bending induced by polarization field at the interface of the last barrier and EBL and the increased carrier distribution uniformity is due to step-like potential height for carrier of the new designed LEDs. In addition, the distribution of radiative recombination rate and the efficiency droop are markedly improved when the conventional GaN barriers are replaced by AlGaN SLBs and the EBL is removed.
KeywordsPolarization Field Internal Quantum Efficiency Carrier Distribution Potential Height Spontaneous Emission Rate
This work was supported by the National Natural Science Foundation of China (Grant No. 61176043), the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong (Grant Nos. 2010A081002005, 2011A081301003, and 2012A080304016), and Youth funding of South China Normal University (Grant No.2012KJ018).
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