Unraveling Efficiency Droop in InGaN-Based Yellow and Green Light-Emitting Diodes via Photoluminescence and Electroluminescence

作者：Liu, Tong; Wang, Hong-Wei; Xiao, Yao; Lin, Yue; Lu, Yi-Jun; Zhu, Li-Hong^*; Zi-QuanGuo; Gao, Yu-Lin; Chen, Guo-Long; Chen, Zhong

来源：Journal of Nanoscience and Nanotechnology, 2018, 18(11): 7542-7547.

DOI：10.1166/jnn.2018.16059

• Light-Emitting Diodes (LEDs)
• Photoluminescence (PL)
• Electroluminescence (EL)
• Carrier Delocalization

Photoluminescence (PL) spectra of yellow and green InGaN-based multiple quantum-well lighte-mitting diodes (LEDs) have been investigated over a wide range of excitation power (4.0 to 245 mW). The efficiency drop has been observed in the PL. Notably, the PL efficiency as a function of excitation power indicates that carrier delocalization is mostly in charge of the efficiency droop at low excitation power and temperature. From the unusual M-and S-shapes of current-dependent EL efficiency at low temperature for yellow and green LEDs respectively, we conclude that the radiative recombination luminescence is mediated initially by the localized states and then by interband transition as injection current increasing. We also found that the efficiency droop in low and high injection current adopts two distinct mechanisms, shedding light on the efficiency droop mechanisms for InGaN-based yellow and green LEDs.

• 出版日期2018-11
• 单位厦门大学