Carrier recombination dynamics in green InGaN-LEDs with quantum-dot-like structures
Exciton localization phenomena are considered here to comprehend the high internal quantum efficiency in InGaN/GaN multiple-quantum-well structures having discrete quantum dots (QDs) prepared by metal–organic-chemical-vapor deposition method on c-sapphire substrates. Spectroscopic results from the variable-temperature steady-state-photoluminescence and time-resolved photoluminescence (TRPL) are investigated. While the exciton localization is enhanced by strong localized states within the InGaN/GaN QDs–the impact of free carrier recombination cannot be ignored. The observed non-exponential decay in TRPL measurements is explained using a model by meticulously including localized exciton, non-radiative and free carrier recombination rates. A new method is proposed to calculate the internal quantum efficiency, which is supplementary to the traditional approach based on temperature-dependent photoluminescence measurement.
Journal of Materials Science
Digital Object Identifier (DOI)
Ming Tian, M. Tian, Cangmin Ma, C. Ma, Tao Lin, T. Lin, Jianping Liu, J. Liu, Devki N. Talwar, D. N. Talwar, Hui Yang, H. Yang, Jiehua Cao, J. Cao, Xinying Huang, X. Huang, Wenlong Niu, W. Niu, Ian T. Ferguson, I. T. Ferguson, Lingyu Wan, L. Wan, & Zhe Chuan Feng, Z. Chuan Feng. (0000). Carrier recombination dynamics in green InGaN-LEDs with quantum-dot-like structures. Journal of materials science, 56, 1481-1491. doi: 10.1007/s10853-020-05343-6