title: Strong localization effect and carrier relaxation dynamics in self-assembled InGaN quantum dots emitting in the green.
abstract: Strong localization effect in self-assembled InGaN quantum dots (QDs) grown by metalorganic chemical vapor deposition has been evidenced by temperature-dependent photoluminescence (PL) at different excitation power. The integrated emission intensity increases gradually in the range from 30 to 160 K and then decreases with a further increase in temperature at high excitation intensity, while this phenomenon disappeared at low excitation intensity. Under high excitation, about 40% emission enhancement at 160 K compared to that at low temperature, as well as a higher internal quantum efficiency (IQE) of 41.1%, was observed. A strong localization model is proposed to describe the possible processes of carrier transport, relaxation, and recombination. Using this model, the evolution of excitation-power-dependent emission intensity, shift of peak energy, and linewidth variation with elevating temperature is well explained. Finally, two-component decays of time-resolved PL (TRPL) with various excitation intensities are observed and analyzed with the biexponential model, which enables us to further understand the carrier relaxation dynamics in the InGaN QDs.
authors: Department of Physics and Semiconductor Photonics Research Center, Xiamen University, 422 South Siming Road, Xiamen, 361005 P. R. China.
authors: Guo-En
authors: GE
authors: Weng
authors: Department of Electronic Engineering, Optoelectronics Engineering Research Center, Xiamen University, 422 South Siming Road, Xiamen, 361005 P. R. China.
authors: Wan-Ru
authors: WR
authors: Zhao
authors: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 Japan ; Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 P. R. China.
authors: Shao-Qiang
authors: SQ
authors: Chen
authors: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 Japan.
authors: Hidefumi
authors: H
authors: Akiyama
authors: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 398 Ruoshui Road, Suzhou, 215123 P. R. China.
authors: Zeng-Cheng
authors: ZC
authors: Li
authors: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 398 Ruoshui Road, Suzhou, 215123 P. R. China.
authors: Jian-Ping
authors: JP
authors: Liu
authors: Department of Electronic Engineering, Optoelectronics Engineering Research Center, Xiamen University, 422 South Siming Road, Xiamen, 361005 P. R. China.
authors: Bao-Ping
authors: BP
authors: Zhang
keywords: Carrier relaxation dynamics; InGaN; Localization effect; Quantum dots