Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures

Mostly, optical spectroscopies are used to investigate the physics of excitons, whereas their electrical evidences are hardly explored. Here, we examined a forward bias activated differential capacitance response of GaInP/AlGaInP based multi-quantum well laser diodes to trace the presence of exciton...

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Main Authors: Bhunia, A., Bansal, Kanika, Henini, M., Alshammari, M.S., Datta, Shouvik
Format: Article
Published: AIP Publishing 2016
Online Access:https://eprints.nottingham.ac.uk/37700/
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author Bhunia, A.
Bansal, Kanika
Henini, M.
Alshammari, M.S.
Datta, Shouvik
author_facet Bhunia, A.
Bansal, Kanika
Henini, M.
Alshammari, M.S.
Datta, Shouvik
author_sort Bhunia, A.
building Nottingham Research Data Repository
collection Online Access
description Mostly, optical spectroscopies are used to investigate the physics of excitons, whereas their electrical evidences are hardly explored. Here, we examined a forward bias activated differential capacitance response of GaInP/AlGaInP based multi-quantum well laser diodes to trace the presence of excitons using electrical measurements. Occurrence of “negative activation energy” after light emission is understood as thermodynamical signature of steady state excitonic population under intermediate range of carrier injections. Similar corroborative results are also observed in an InGaAs/GaAs quantum dot laser structure grown by molecular beam epitaxy. With increasing biases, the measured differential capacitance response slowly vanishes. This represents gradual Mott transition of an excitonic phase into an electron-hole plasma in a GaInP/AlGaInP laser diode. This is further substantiated by more and more exponentially looking shapes of high energy tails in electroluminescence spectra with increasing forward bias, which originates from a growing non-degenerate population of free electrons and holes. Such an experimental correlation between electrical and optical properties of excitons can be used to advance the next generation excitonic devices.
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spelling nottingham-377002020-05-04T18:17:10Z https://eprints.nottingham.ac.uk/37700/ Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures Bhunia, A. Bansal, Kanika Henini, M. Alshammari, M.S. Datta, Shouvik Mostly, optical spectroscopies are used to investigate the physics of excitons, whereas their electrical evidences are hardly explored. Here, we examined a forward bias activated differential capacitance response of GaInP/AlGaInP based multi-quantum well laser diodes to trace the presence of excitons using electrical measurements. Occurrence of “negative activation energy” after light emission is understood as thermodynamical signature of steady state excitonic population under intermediate range of carrier injections. Similar corroborative results are also observed in an InGaAs/GaAs quantum dot laser structure grown by molecular beam epitaxy. With increasing biases, the measured differential capacitance response slowly vanishes. This represents gradual Mott transition of an excitonic phase into an electron-hole plasma in a GaInP/AlGaInP laser diode. This is further substantiated by more and more exponentially looking shapes of high energy tails in electroluminescence spectra with increasing forward bias, which originates from a growing non-degenerate population of free electrons and holes. Such an experimental correlation between electrical and optical properties of excitons can be used to advance the next generation excitonic devices. AIP Publishing 2016-10-13 Article PeerReviewed Bhunia, A., Bansal, Kanika, Henini, M., Alshammari, M.S. and Datta, Shouvik (2016) Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures. Journal of Applied Physics, 120 . 144304/1-144304/10. ISSN 1089-7550 http://scitation.aip.org/content/aip/journal/jap doi:10.1063/1.4964850 doi:10.1063/1.4964850
spellingShingle Bhunia, A.
Bansal, Kanika
Henini, M.
Alshammari, M.S.
Datta, Shouvik
Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title_full Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title_fullStr Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title_full_unstemmed Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title_short Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
title_sort negative activation energy and dielectric signatures of excitons and excitonic mott transitions in quantum confined laser structures
url https://eprints.nottingham.ac.uk/37700/
https://eprints.nottingham.ac.uk/37700/
https://eprints.nottingham.ac.uk/37700/