[1] Kuo Y K, Chang J Y, Tsai M C, et al. Advantages of blue InGaN multiple-quantum well light-emitting diodes with InGaN barriers[J]. Appl. Phys. Lett., 2009, 95: 011116.
[3] Kim M H, Schubert M F, Dai Q, et al. Origin of efficiency droop in GaN-based light-emitting diodes[J]. Appl. Phys. Lett., 2007, 91: 183507.
[4] Wu L J, Li S T, Liu C, et al. Simulation study of blue InGaN multiple quantum well light-emitting diodes with different hole injection layers[J]. Chin. Phys. B, 2012, 21: 068506.
[5] Lu T P, Li S T, et al. Advantages of GaN based light-emitting diodes with a p-InGaN hole reservoir layer[J]. Appl. Phys. Lett., 2012, 100: 141106.
[6] Lin G B, Shan Q F, Wang Y, et al. “U-turn” feature in the efficiency-versus-current curve of GaInN/GaN light-emitting diodes[J]. Appl. Phys. Lett., 2014, 105: 221116.
[7] Chung H J, Choi R J, Kim M H, et al. Improved performance of GaN-based blue light emitting diodes with InGaN/GaN multilayer barriers[J]. Appl. Phys. Lett., 2009, 95: 241109.
[8] Becerra D L, Zhao Y, Oh S H, et al. High-power low-droop violet semipolar (303-1-) InGaN/GaN light-emitting diodes with thick active layer design[J]. Appl. Phys. Lett., 2014, 105: 171106.
[9] Kim M H, Schubert M F, Dai Q, et al. Origin of efficiency droop in GaN-based light-emitting diodes[J]. Appl. Phys. Lett., 2007, 91: 183507.
[10] Bernardini F, Fiorentini V, et al. Spontaneous polarization and piezoelectric constants of III-V nitrides[J]. Phys. Rev. B, 1997, 56: R10024.
[11] Lu T P, Li S T, Zhang K, et al. Blue InGaN light-emitting diodes with dip-shaped quantum wells[J]. Chin. Phys. B, 2011, 20: 108504.
[12] Lu T P, Li S T, Zhang K, et al. Effect of the thickness of undoped GaN interlayers between multiple quantum wells and the p-doped layer on the performance of GaN light-emitting diodes[J]. Opt. Expr., 2011, 19: 18320.
[13] Arif R A, Zhao H, Ee Y K, et al. Spontaneous emission and haracteristics of staggered InGaN quantum-well light-emitting diodes[J]. IEEE J. Quantum Electron., 2008, 44 (6): 573-580.
[14] Jun P, Dong Y K, Sunyong H, et al. Enhanced overall efficiency of GaInN-based light-emitting diodes with reduced efficiency droop by Al-composition-graded AlGaN/GaN superlattice electron blocking layer[J]. Appl. Phys. Lett., 2013, 103: 061104.
[15] Wang C H, Chang S P, Chang W T, et al. Efficiency droop alleviation in InGaN/GaN light-emitting diodes by graded-thickness multiple quantum wells[J]. Appl. Phys. Lett., 2010, 97: 181101.