Correlating Photoluminescence and Structural Properties of Uncapped and GaAs-Capped Epitaxial InGaAs Quantum Dots

Scientific Reports
Arka B DeyVinayak Dravid

Abstract

The understanding of the correlation between structural and photoluminescence (PL) properties of self-assembled semiconductor quantum dots (QDs), particularly InGaAs QDs grown on (001) GaAs substrates, is crucial for both fundamental research and optoelectronic device applications. So far structural and PL properties have been probed from two different epitaxial layers, namely top-capped and buried layers respectively. Here, we report for the first time both structural and PL measurements from an uncapped layer of InGaAs QDs to correlate directly composition, strain and shape of QDs with the optical properties. Synchrotron X-ray scattering measurements show migration of In atom from the apex of QDs giving systematic reduction of height and enlargement of QDs base in the capping process. The optical transitions show systematic reduction in the energy of ground state and the first excited state transition lines with increase in capping but the energy of the second excited state line remain unchanged. We also found that the excitons are confined at the base region of these elliptically shaped QDs showing an interesting volume-dependent confinement energy scaling of 0.3 instead of 0.67 expected for spherical dots. The presented met...Continue Reading

References

Jul 15, 1995·Physical Review. B, Condensed Matter·A PatanèF Martelli
Apr 6, 2001·Physical Review Letters·T WaltherM Hopkinson
Oct 13, 2007·Physical Review Letters·N A J M KleemansP M Koenraad
Jul 14, 2011·Advanced Materials·Pierre M Petroff
Feb 3, 2012·Advanced Materials·Diego Alonso-ÁlvarezFernando Briones

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Citations

Jul 27, 2021·Journal of Physics. Condensed Matter : an Institute of Physics Journal·Arka Bikash DeyKalobaran Maiti

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Methods Mentioned

BETA
atomic
X-ray
AFM
transmission electron microscopy
Atomic Force Microscopy

Software Mentioned

Matlab

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