Indium-Induced Effect on Polarized Electroluminescence from InGaN/GaN MQWs Light Emitting Diodes
RUAN Jun1,2, YU Tong-Jun1, JIA Chuan-Yu1, TAO Ren-Chun1, WANG Zhan-Guo2, ZHANG Guo-Yi1
1State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 1008712Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083
Indium-Induced Effect on Polarized Electroluminescence from InGaN/GaN MQWs Light Emitting Diodes
RUAN Jun1,2, YU Tong-Jun1, JIA Chuan-Yu1, TAO Ren-Chun1, WANG Zhan-Guo2, ZHANG Guo-Yi1
1State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 1008712Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083
摘要Polarization-resolved edge-emitting electroluminescence (EL) studies of InGaN/GaN MQWs of wavelengths from near-UV (390nm) to blue (468nm) light-emitting diodes (LEDs) are performed. Although the TE mode is dominant in all the samples of InGaN/GaN MQW LEDs, an obvious difference of light polarization properties is found in the InGaN/GaN MQW LEDs with different wavelengths. The polarization degree decreases from 52.4% to 26.9% when light wavelength increases. Analyses of band structures of InGaN/GaN quantum wells and luminescence properties of quantum dots imply that quantum-dot-like behavior is the dominant reason for the low luminescence polarization degree of blue LEDs, and the high luminescence polarization degree of UV LEDs mainly comes from QW confinement and the strain effect. Therefore, indium induced carrier confinement (quantum-dot-like behavior) might play a major role in the polarization degree change of InGaN/GaN MQW LEDs from near violet to blue.
Abstract：Polarization-resolved edge-emitting electroluminescence (EL) studies of InGaN/GaN MQWs of wavelengths from near-UV (390nm) to blue (468nm) light-emitting diodes (LEDs) are performed. Although the TE mode is dominant in all the samples of InGaN/GaN MQW LEDs, an obvious difference of light polarization properties is found in the InGaN/GaN MQW LEDs with different wavelengths. The polarization degree decreases from 52.4% to 26.9% when light wavelength increases. Analyses of band structures of InGaN/GaN quantum wells and luminescence properties of quantum dots imply that quantum-dot-like behavior is the dominant reason for the low luminescence polarization degree of blue LEDs, and the high luminescence polarization degree of UV LEDs mainly comes from QW confinement and the strain effect. Therefore, indium induced carrier confinement (quantum-dot-like behavior) might play a major role in the polarization degree change of InGaN/GaN MQW LEDs from near violet to blue.
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2009, Vol. 26 
