Carrier recombination dynamics in electronically coupled multi-layer InAs/GaAs quantum dots

Mohanta, Antaryami; Jang, Der-Jun; Lu, Shu-Kai; Ling, D. C.; Wang, J.S.; Chen, R.-B.; Chuang, Feng‐Chuan

doi:10.1016/j.jlumin.2017.11.009

Cited by 2 publications

(2 citation statements)

References 27 publications

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“…However, in this study the average lifetime has also been found to decrease in the lower energy side (E<GS), contrary to the observed variation of carrier lifetime [64,65]. Previously, several groups have reported similar kind of phenomena in their studies [18,20,41,66]. We interpret that the observed variation of average lifetime is due to difference in confinement of the electron wave function in the growth direction, which results in a different electron and hole wave function overlapping for different-sized QDs.…”

Section: Photoluminescence Resultscontrasting

confidence: 72%

“…After Gaussian curve fitting of the power dependent photoluminescence spectra, it has been observed that the dot size distribution is mono-modal and the origin of the two peaks in the PL is due to two different transitions. The main peak at lower energy resembles the ground state transition (E 0 -HH) and the shoulder peak at higher energy denotes the 1st excited state transition (E 1 -LH) [41]. Here E 0 and E 1 denote the 'ground state'(GS) and '1st excited state' of conduction band respectively and HH and LH represent the 'heavy hole' and 'light hole' component of the valance band in the InAs QD.…”

Section: Photoluminescence Resultsmentioning

confidence: 99%

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Strain relaxation in InAs quantum dots through capping layer variation and its impact on the ultrafast carrier dynamics

Chatterjee

Panda

Patwari

et al. 2019

Semicond. Sci. Technol.

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Ultrafast carrier dynamics is found to be crucial for influencing the efficiency of quantum dot (QD)-based optoelectronic devices. Here, we have studied picosecond resolved dynamics in InAs semiconductor quantum dots forming various heterostructure geometries with their different capping layers. The carriers (electron-hole pairs) are optically injected into three dimensional heterostructure barriers after which, we monitor the carrier relaxation into the zerodimensional InAs dots by using picosecond resolved time correlated single photon counting technique. We have explicitly investigated and analyzed the effect of three different capping layers, GaAs (binary), In 0.15 Ga 0.85 As/GaAs (ternary) and In 0.21 Al 0.21 Ga 0.58 As/GaAs (quaternary) offering various optical properties of InAs quantum dots. It has been observed that quaternary strain reducing layer effectively suppresses Indium migration from the QDs and enhances the confinement of carriers inside the QD heterostructures. In this study, we also find that thermal stability of the carriers is improved in the quaternary capped QDs more effectively compared to the conventional binary and ternary capped one. In brief, our experiments provide essential insight into carrier relaxation in the InAs QDs across various capping layers.

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