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Experimental Detection and Control of Trions and Fermi-Edge Singularity in Single-Barrier GaAs/AlAs/GaAs Heterostructures Using Photocapacitance Spectroscopy

Bhunia, Amit; Singh, Mohit Kumar; Gobato, Y. Galv�o; Henini, Mohamed; Datta, Shouvik

Authors

Amit Bhunia

Mohit Kumar Singh

Y. Galv�o Gobato

Shouvik Datta



Abstract

© 2018 American Physical Society. We show how photocapacitance spectra can probe and manipulate two dimensional excitonic complexes and Fermi-edge singularities as a function of applied bias even at a temperature of 100 K. For lower density regimes (1×1011cm-2), we observe a sharp spectral transition from trions to asymmetrically shaped Fermi-edge singularities in photocapacitance spectra above a particular reverse bias. However, these signatures of indirect excitonic states are absent from photoluminescence spectra. Such dissimilarities clearly point out that different many body physics govern these two spectral measurements. We also argue why such quantum-confined dipoles of spatially indirect trions can have thermodynamically finite probability to survive even around 100 K. Finally, our observations demonstrate that photocapacitance spectroscopy, which was rarely used to detect trions in the past, can also be useful to detect the traces of these spatially indirect excitonic complexes as well as Fermi-edge singularities. This is mainly due to the enhanced sensitivity of these capacitive measurements to "dipolar" changes of excitonic complexes in these heterojunctions. Thus, our studies clearly open up future possibilities for electro-optical modulation and detection of trions and Fermi-edge singularities in several other heterostructures for next-generation optoelectronic applications.

Citation

Bhunia, A., Singh, M. K., Gobato, Y. G., Henini, M., & Datta, S. (2018). Experimental Detection and Control of Trions and Fermi-Edge Singularity in Single-Barrier GaAs/AlAs/GaAs Heterostructures Using Photocapacitance Spectroscopy. Physical Review Applied, 10(4), Article 044043. https://doi.org/10.1103/physrevapplied.10.044043

Journal Article Type Article
Acceptance Date Jul 9, 2018
Online Publication Date Oct 17, 2018
Publication Date Oct 17, 2018
Deposit Date Oct 20, 2018
Publicly Available Date Mar 29, 2024
Journal Physical Review Applied
Electronic ISSN 2331-7019
Publisher American Physical Society
Peer Reviewed Peer Reviewed
Volume 10
Issue 4
Article Number 044043
DOI https://doi.org/10.1103/physrevapplied.10.044043
Public URL https://nottingham-repository.worktribe.com/output/1177478
Publisher URL https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.10.044043
Additional Information ©2018 American Physical Society

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