We demonstrate that all the available experimental data of temperature (T)-dependent shift of photoluminescence (PL) peak of In(Ga)As quantum dots (QDs) can be fitted successfully by using a two-oscillator model if and only if the whole temperature interval (0–300 K) is divided into a few parts (at most four parts), depending on dispersion degree of the PL peak from a monotonic behavior. Analysis of the numerical results show that excitons mostly interact (inelastically) with acoustic (AC) or optical (OP) phonons separately. Increasing QDs uniformity, by using some improved growth techniques, results in decreasing or removing the sigmoidal behavior, enhancing total AC phonon contribution and the maximum temperature that AC phonons contribute to the -dependent redshift of the PL peak. Elevation of the zero bandgap (ZBG) energy up to a critical value about 1.4 eV, for In(Ga)As QDs grown using molecular-beam epitaxy, results in enhancement of QD symmetry and total OP phonon contribution and decline of QDs uniformity and total AC phonon contribution, while a rollover happens for further increase of the ZBG. Therefore we find that the highest QD symmetry and the lowest exciton fine structure splitting correspond to this critical value of ZBG, in accordance with previous experimental results.
© 2014 Optical Society of AmericaFull Article | PDF Article
J. Opt. Soc. Am. B 19(7) 1692-1705 (2002)
Jianfeng Xu, David Battaglia, Xiaogang Peng, and Min Xiao
J. Opt. Soc. Am. B 22(5) 1112-1116 (2005)
Demetrios N. Christodoulides, Iam Choon Khoo, Gregory J. Salamo, George I. Stegeman, and Eric W. Van Stryland
Adv. Opt. Photon. 2(1) 60-200 (2010)