Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature
We investigated excitonic absorptions in a GaAs/AlAs/GaAs single barrier heterostructure using both photocapacitance and photocurrent spectroscopies at room temperature. Photocapacitance spectra show well defined resonance peaks of indirect excitons formed around the C-AlAs barrier. Unlike DC-photoc...
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| Format: | Article |
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AIP Publishing
2018
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| Online Access: | https://eprints.nottingham.ac.uk/49487/ |
| _version_ | 1848798008527814656 |
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| author | Bhunia, Amit Singh, Mohit Kumar Galvao Gobato, Y. Henini, M. Datta, Shouvik |
| author_facet | Bhunia, Amit Singh, Mohit Kumar Galvao Gobato, Y. Henini, M. Datta, Shouvik |
| author_sort | Bhunia, Amit |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We investigated excitonic absorptions in a GaAs/AlAs/GaAs single barrier heterostructure using both photocapacitance and photocurrent spectroscopies at room temperature. Photocapacitance spectra show well defined resonance peaks of indirect excitons formed around the C-AlAs barrier. Unlike DC-photocurrent spectra, frequency dependent photocapacitance spectra interestingly red shift, sharpen up, and then decrease with increasing tunneling at higher biases. Such dissimilarities clearly point out that different exciton dynamics govern these two spectral measurements. We also argue why such quantum confined dipoles of indirect excitons can have thermodynamically finite probabilities to survive even at room temperature. Finally, our observations demonstrate that the photocapacitance technique, which was seldom used to detect excitons in the past, is useful for selective detection and experimental tuning of relatively small numbers ( 1011/cm2) of photo-generated indirect excitons having large effective dipole moments in this type of quasi-two dimensional heterostructures. |
| first_indexed | 2025-11-14T20:12:56Z |
| format | Article |
| id | nottingham-49487 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:12:56Z |
| publishDate | 2018 |
| publisher | AIP Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-494872020-05-04T19:28:49Z https://eprints.nottingham.ac.uk/49487/ Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature Bhunia, Amit Singh, Mohit Kumar Galvao Gobato, Y. Henini, M. Datta, Shouvik We investigated excitonic absorptions in a GaAs/AlAs/GaAs single barrier heterostructure using both photocapacitance and photocurrent spectroscopies at room temperature. Photocapacitance spectra show well defined resonance peaks of indirect excitons formed around the C-AlAs barrier. Unlike DC-photocurrent spectra, frequency dependent photocapacitance spectra interestingly red shift, sharpen up, and then decrease with increasing tunneling at higher biases. Such dissimilarities clearly point out that different exciton dynamics govern these two spectral measurements. We also argue why such quantum confined dipoles of indirect excitons can have thermodynamically finite probabilities to survive even at room temperature. Finally, our observations demonstrate that the photocapacitance technique, which was seldom used to detect excitons in the past, is useful for selective detection and experimental tuning of relatively small numbers ( 1011/cm2) of photo-generated indirect excitons having large effective dipole moments in this type of quasi-two dimensional heterostructures. AIP Publishing 2018-01-31 Article PeerReviewed Bhunia, Amit, Singh, Mohit Kumar, Galvao Gobato, Y., Henini, M. and Datta, Shouvik (2018) Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature. Journal of Applied Physics, 123 (4). 044305/1-044305/8. ISSN 1089-7550 http://aip.scitation.org/doi/10.1063/1.5007820 doi:10.1063/1.5007820 doi:10.1063/1.5007820 |
| spellingShingle | Bhunia, Amit Singh, Mohit Kumar Galvao Gobato, Y. Henini, M. Datta, Shouvik Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title | Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title_full | Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title_fullStr | Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title_full_unstemmed | Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title_short | Experimental evidences of quantum confined 2D indirect excitons in single barrier GaAs/AlAs/GaAs heterostructure using photocapacitance at room temperature |
| title_sort | experimental evidences of quantum confined 2d indirect excitons in single barrier gaas/alas/gaas heterostructure using photocapacitance at room temperature |
| url | https://eprints.nottingham.ac.uk/49487/ https://eprints.nottingham.ac.uk/49487/ https://eprints.nottingham.ac.uk/49487/ |