One order enhancement of detectivity in quaternary capped InAs/GaAs quantum dot infrared photodetectors due to vertical coupling of quantum dot layers
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Title |
One order enhancement of detectivity in quaternary capped InAs/GaAs quantum dot infrared photodetectors due to vertical coupling of quantum dot layers
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Creator |
GHADI, H
AGARWAL, A ADHIKARY, S AGAWANE, J MANDAL, A CHAKRABARTI, S PENDYALA, NB PRAJAPATI, S |
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Subject |
Indium aluminum gallium arsenide
Quaternary capping Quantum dot Infrared photodetector Vertical coupling Strain coupling HIGH-TEMPERATURE INAS ISLANDS GAAS EMISSION GROWTH WAVELENGTH WELL |
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Description |
The spectral and electrical properties of vertically coupled quaternary (InAlGaAs) capped InAs/GaAs quantum dot infrared photodetector with different capping thicknesses are investigated, and compared with a conventional quaternary capped uncoupled detector. Electronic coupling between quantum dot layers leads to a reduction in the ground state energy level and hence greater electronic confinement, which reduces the dark current and enhances the detectivity. These expectations are confirmed by our experimental results. Most significantly one order enhancement in peak detectivity (from 1.1 x 10(9) cm Hz(1/2)/W to 2.48 x 10(10) cm Hz(1/2)/W) is observed for optimized coupled quantum dot infrared photodetector compared to uncoupled device. The optimal interlayer barrier thickness which gives maximum detectivity is explained in terms of the interplay between electronic coupling and strain buildup in the heterostructure. (C) 2014 Elsevier B.V. All rights reserved.
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Publisher |
ELSEVIER SCIENCE SA
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Date |
2014-12-29T05:29:38Z
2014-12-29T05:29:38Z 2014 |
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Type |
Article
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Identifier |
THIN SOLID FILMS, 5661-4
0040-6090 http://dx.doi.org/10.1016/j.tsf.2014.07.010 http://dspace.library.iitb.ac.in/jspui/handle/100/17196 |
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Language |
English
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