4 Niu Q L, Zhang Y, Wang Y L, et al. High-efficiency conjugated-polymer-hosted blue phosphorescent light-emitting diodes. Chin Sci Bull, 2012, 57: 3639-3643
[2]
6 Zhang W W, Wu Z X, Zhang X W, et al. Dependence of the stability of organic light-emitting diodes on driving mode. Chin Sci Bull, 2011, 56: 2210-2214
[3]
7 Jiang H J. Effective adjustment of the optoelectronic properties of organic conjugated materials by synthesizing p-n diblock molecules. Chin Sci Bull, 2011, 56: 119-136
[4]
8 Meng L C, Lou Z D, Yang S Y, et al. Energy distribution in white organic light-emitting diodes with three primary color emitting layers. Sci China-Phys Mech Astron, 2011, 54: 84-88
11 Kim M H, Schubert M F, Dai Q, et al. Origin of efficiency droop in GaN-based light-emitting diodes. Appl Phys Lett, 2007, 91: 183507
[7]
13 Choi S, Kim H J, Kim S S, et al. Improvement of peak quantum efficiency and efficiency droop in Ⅲ-nitride visible light-emitting diodes with an InAlN electron-blocking layer. Appl Phys Lett, 2010, 96: 221105
[8]
18 Han S H, Lee D Y, Shim H W, et al. Improvement of efficiency droop in InGaN/GaN multiple quantum well light-emitting diodes with trapezoidal wells. J Phys D Appl Phys, 2010, 43: 354004
[9]
19 Lee Y J, Chen C H, Lee C J. Reduction in the Efficiency-droop effect of InGaN green light-emitting diodes using gradual quantum wells. IEEE Photon Technol Lett, 2010, 22: 1506-1508
[10]
20 Chang J Y, Tsai M C, Kuo Y K. Advantages of blue InGaN light-emitting diodes with AlGaN barriers. Opt Lett, 2010, 35: 1368-1370
[11]
21 Kuo Y K, Chang J Y, Tsai M C, et al. Advantages of blue InGaN multiple-quantum well light-emitting diodes with InGaN barriers. Appl Phys Lett, 2009, 95: 011116
[12]
24 Tsai M C, Yen S H, Kuo Y K. Deep-ultraviolet light-emitting diodes with gradually increased barrier thicknesses from n-layers to p-layers. Appl Phys Lett, 2011, 98: 111114
[13]
25 Wang C H, Chang S P, Ku P H, et al. Hole transport improvement in InGaN/GaN light-emitting diodes by graded-composition multiple quantum barriers. Appl Phys Lett, 2011, 99: 171106
[14]
26 Ni X, Fan Q, Shimada R, et al. Reduction of efficiency droop in InGaN light emitting diodes by coupled quantum wells. Appl Phys Lett, 2008, 93: 171113
[15]
28 Yen S H, Tsai M C, Tsai M L, et al. Effect of n-type AlGaN layer on carrier transportation and efficiency droop of blue InGaN light-emitting diodes. IEEE Photon Technol Lett, 2009, 21: 975-977
[16]
29 Lee K B, Parbrook P J, Wang T, et al. Effect of the AlGaN electron blocking layer thickness on the performance of AlGaN-based ultraviolet light-emitting diodes. J Crystal Growth, 2009, 311: 2857-2859
[17]
30 Xia C S, Li Z M, Lu W, et al. Efficiency enhancement of blue InGaN/GaN light-emitting diodes with an AlGaN-GaN-AlGaN electron blocking layer. J Appl Phys, 2012, 111: 094503
[18]
31 Kuo Y K, Chang J Y, Tsai M C. Enhancement in hole-injection efficiency of blue InGaN light-emitting diodes from reduced polarization by some specific designs for the electron blocking layer. Opt Lett, 2010, 35: 3285-3287
[19]
34 Kuo Y K, Tsai M C, Yen S H, et al. Effect of p-type last barrier on efficiency droop of blue InGaN light-emitting diodes. IEEE J Quant Electron, 2010, 46: 1214-1220
[20]
35 Kuo Y K, Shih Y H, Tsai M C, et al. Improvement in electron overflow of near-ultraviolet InGaN LEDs by specific design on last barrier. IEEE Photon Technol Lett, 2011, 23: 1630-1632
[21]
36 Yen S H, Tsai M L, Tsai M C, et al. Investigation of optical performance of InGaN MQW LED with thin last barrier. IEEE Photon Technol Lett, 2010, 22: 1787-1789
[22]
38 Shen Y C, Mueller G O, Watanabe S, et al. Auger recombination in InGaN measured by photoluminescence. Appl Phys Lett, 2007, 91: 141101
[23]
39 Chen J R, Wu Y C, Ling S C, et al. Investigation of wavelength-dependent efficiency droop in InGaN light-emitting diodes. Appl Phys B, 2010, 98: 779-789
[24]
44 Chuang S L, Chang C S. k·p method for strained wurtzite semiconductors. Phys Rev B, 1996, 54: 2491-2504
[25]
46 Vurgaftman I, Meyer J R, Ram-Mohan L R. Band parameters for Ⅲ-Ⅴ compound semiconductors and their alloys. J Appl Phys, 2001, 89: 5815-5875
[26]
47 Vurgaftman I, Meyer J R. Band parameters for nitrogen containing semiconductors. J Appl Phys, 2003, 94: 3675-3696
[27]
49 Renner F, Kiesel P, D?hler G H, et al. Quantitative analysis of the polarization fields and absorption changes in InGaN/GaN quantum wells with electroabsorption spectroscopy. Appl Phys Lett, 2002, 81: 490-492
[28]
50 Zhang H, Miller E J, Yu E T, et al. Measurement of polarization charge and conduction-band offset at InxGa1-xN/GaN heterojunction interfaces. Appl Phys Lett, 2004, 84: 4644-4646
[29]
51 Caughey C M, Thomas R E. Carrier mobilities in silicon empirically related to doping and field. Proc IEEE, 1967, 55: 2192-2193
[30]
52 Piprek J. Semiconductor Optoelectronic Devices: Introduction to Physics and Simulation. London: Academic Press, 2003. 45-147
55 Huang S, Wu H, Fan B, et al. A chip-level electro thermal coupled design model for high-power light-emitting diodes. J Appl Phys, 2010, 107: 054509
[33]
1 Schubert E F, Kim J K. Solid-state light sources getting smart. Science, 2005, 208: 1274-1278
[34]
2 Krames M R, Shchekin O B, Mueller-Mach R, et al. Status and future of high-power light-emitting diodes for solid-state lighting. J Disp Technol, 2007, 3: 160-175
[35]
3 Crawford M H. LEDs for solid-state lighting: Performance challenges and recent advances. IEEE J Sel Top Quantum Electron, 2009, 15: 1028-1040
[36]
5 Xu Y Q, Fan G H, Zhou D T, et al. Advantage of dual wavelength light-emitting diodes with dip-shaped quantum wells. Chin Sci Bull, 2012, 57: 2562-2566
[37]
9 Wang X L, Wang X H, Jia H Q, et al. Recent progress in single chip white light-emitting diodes with the InGaN underlying layer. Sci China-Phys Mech Astron, 2010, 53: 445-448
[38]
12 Schubert M F, Xu J, Kim J K, et al. Polarization-matched GaInN/AlGaInN multi-quantum-well light emitting diodes with reduced efficiency droop. Appl Phys Lett, 2008, 93: 041102
[39]
14 Wang C H, Chen J R, Chiu C H, et al. Temperature dependent electroluminescence efficiency in blue InGaN-GaN light emitting diodes with different well widths. IEEE Photon Technol Lett, 2010, 22: 236-238
[40]
15 Zhao H P, Liu G Y, Zhang J, et al. Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells. Opt Express, 2011, 19: A991-A1007
[41]
16 Ding K, Zeng Y P, Wei X C, et al. A wide-narrow well design for understanding the efficiency droop in InGaN/GaN light-emitting diodes. Appl Phys B, 2009, 97: 465-468
[42]
17 Li Y L, Huang Y R, Lai Y H. Efficiency droop behaviors of InGaN/GaN multiple-quantum-well light-emitting diodes with varying quantum well thickness. Appl Phys Lett, 2007, 91: 181113
[43]
22 Kuo Y K, Wang T H, Chang J Y. Advantages of blue InGaN light-emitting diodes with InGaN-AlGaN-InGaN barriers. Appl Phys Lett, 2012, 100: 031112
[44]
23 Liu J P, Ryou J H, Dupuis R D, et al. Barrier effect on hole transport and carrier distribution in InGaN/GaN multiple quantum well visible light-emitting diodes. Appl Phys Lett, 2008, 93: 021102
[45]
27 Han S H, Lee D Y, Lee S J, et al. Effect of electron blocking layer on efficiency droop in InGaN/GaN multiple quantum well light-emitting diodes. Appl Phys Lett, 2009, 94: 231123
[46]
32 Wang C H, Ke C C, Lee C Y, et al. Hole injection and efficiency droop improvement in InGaN/GaN light-emitting diodes by band-engineered electron blocking layer. Appl Phys Lett, 2010, 97: 261103
[47]
33 Xia C S, Li Z M, Lu W, et al. Droop improvement in blue InGaN/GaN multiple quantum well light-emitting diodes with indium graded last barrier. Appl Phys Lett, 2011, 99: 233501
[48]
37 Chen J R, Lu T C, Kuo H C, et al. Study of InGaN-GaN light-emitting diodes with different last barrier thicknesses. IEEE Photon Technol Lett, 2010, 22: 860-862
[49]
40 Efremov A A, Bochkareva N I, Gorbunov R I, et al. Effect of the Joule heating on the quantum efficiency and choice of thermal conditions for high-power blue InGaN/GaN LEDs. Semiconductors, 2006, 40: 605-610
[50]
41 Chen Y X, Shen G D, Guo W L, et al. Internal quantum efficiency drop induced by the heat generation inside of light emitting diodes (LEDs). Chin Phys B, 2011, 20: 017204
43 Ryu H Y, Shim J I, Kim C H, et al. Efficiency and electron leakage characteristics in GaN-based light-emitting diodes without AlGaN electron-blocking-layer structures. IEEE Photon Technol Lett, 2011, 23: 1866-1868
[53]
45 Chuang S L, Chang C S. A band-structure model of strained quantum-well wurtzite semiconductors. Semicond Sci Technol, 1997, 12: 252-263
[54]
48 Fiorentini V, Bernardini F, Ambacher O. Evidence for nonlinear macroscopic polarization in Ⅲ-Ⅴ nitride alloy heterostructures. Appl Phys Lett, 2002, 80: 1204-1206
[55]
54 Lee H K, Yu J S, Lee Y T. Thermal analysis and characterization of the effect of substrate thinning on the performances of GaN-based light emitting diodes. Phys Status Solid A, 2010, 207: 1497-1504
[56]
56 Xu J L, Wang T H. Efficiency droop improvement for InGaN-based light-emitting diodes with gradually increased In-composition across the active region. Physica E, 2013, 52: 8-13