In this paper,1 we investigated the photoinduced entropy of InGaN/GaN p-i-n nanowires using temperature-dependent (6–290 K) photoluminescence. We also analyzed the photocarrier dynamics in the InGaN active regions using time-resolved photoluminescence. An increasing trend in the amount of photoinduced entropy of the system above 250 K was observed, while we observed an oscillatory trend in the generated entropy of the system below 250 K that stabilizes between 200 and 250 K. Strong exciton localization in indium-rich clusters, carrier trapping by surface defect states, and thermodynamic entropy effects were examined and related to the photocarrier dynamics. We conjectured that the amount of photoinduced entropy of the system increases as more non-radiative channels become activated and more shallowly localized carriers settle into deeply localized states; thereby, additional degrees of uncertainty related to the energy of states involved in thermionic transitions are attained.
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1Photoinduced entropy of InGaN/GaN p-i-n double-heterostructure nanowires
N. Alfaraj, S. Mitra, F. Wu, I. A. Ajia, B. Janjua, A. Prabaswara, R. A. Aljefri, H. Sun, T. K. Ng, B. S. Ooi, I. S. Roqan, and X. Li
Applied Physics Letter (2017)
Published online on April 17, 2017.