Effect of high energy proton irradiation on In As/GaAs quantum dots: Enhancement of photoluminescence efficiency (up to similar to 7 times) with minimum spectral signature shift
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Title |
Effect of high energy proton irradiation on In As/GaAs quantum dots: Enhancement of photoluminescence efficiency (up to similar to 7 times) with minimum spectral signature shift
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Creator |
SREEKUMAR, R
MANDAL, A GUPTA, SK CHAKRABARTI, S |
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Subject |
TEMPERATURE-DEPENDENCE
OPTICAL-PROPERTIES EMISSION IMPLANTATION LASERS WELLS GAAS WAVELENGTH DEFECTS Electronic materials Epitaxial growth X-ray diffraction Defects Optical properties |
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Description |
We demonstrate 7-fold increase of photoluminescence efficiency in GaAs/(InAs/GaAs) quantum dot hetero-structure, employing high energy proton irradiation, without any post-annealing treatment. Protons of energy 3-5 MeV with fluence in the range (1.2-7.04) x 10(12) ions/cm(2) were used for irradiation. X-ray diffraction analysis revealed crystalline quality of the GaAs cap layer improves on proton irradiation. Photoluminescence study conducted at low temperature and low laser excitation density proved the presence of non-radiative recombination centers in the system which gets eliminated on proton irradiation. Shift in photoluminescence emission towards higher wavelength upon irradiation substantiated the reduction in strain field existed between GaAs cap layer and InAs/GaAs quantum dots. The enhancement in PL efficiency is thus attributed to the annihilation of defects/non-radiative recombination centers present in GaAs cap layer as well as in InAs/GaAs quantum dots induced by proton irradiation. (C) 2011 Elsevier Ltd. All rights reserved.
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Publisher |
PERGAMON-ELSEVIER SCIENCE LTD
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Date |
2012-06-26T07:37:38Z
2012-06-26T07:37:38Z 2011 |
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Type |
Article
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Identifier |
MATERIALS RESEARCH BULLETIN,46(11)1786-1793
0025-5408 http://dx.doi.org/10.1016/j.materresbull.2011.07.048 http://dspace.library.iitb.ac.in/jspui/handle/100/14154 |
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Language |
English
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