A study of recombination centres in electron irradiated silicon solar cells
A study of recombination centres in electron irradiated silicon solar cells
Firstly the basic principles involved in the generation and recombination of electron-hole pairs is reviewed and the physics of particle irradiation is discussed. The properties of shallow and deep levels are also discussed and these deep level defects are then examined in detail. The characterisation technique known as Deep Level Transient Spectroscopy (DLTS) and some related techniques are then reviewed and the silicon solar cells used for this investigation are described.
The electrical properties of silicon solar cells doped with either boron, gallium, indium, aluminium or phosphorus formed on a variety of substrates are then determined before and after electron irradiation. The reduction in minority-carrier diffusion length caused by particle irradiation is deduced from these results by fitting the experimental data to a theoretical model. DLTS is then used to identify and categorise the deep levels present in these samples after particle irradiation. A new version of the forward bias DLTS technique is then defined and used to determine the minority-carrier capture cross-section of the positive charge state of the divacancy (VV+/0).
The Shockley-Read-Hall (SRH) model is then used to determine the minority-carrier lifetime of each of the observed defects in the gallium-doped cells. This model is then extended to show that the VV+/0 defect is mainly responsible for the lifetime degradation observed in irradiated czochralski silicon solar cells. The damage coefficients are then determined for all of the cells examined in this study and they were compared to the literature data. Finally it is shown that the commonly observed relationship between the doping density and damage coefficient in silicon solar cells can be explained simply in terms of the divacancies (VV+/0) capture cross-section, introduction rate, and its probability of occupation.
University of Southampton
Smith, Robert Roland
5e81ee58-0795-4444-b2ca-60ec599c492b
2002
Smith, Robert Roland
5e81ee58-0795-4444-b2ca-60ec599c492b
Smith, Robert Roland
(2002)
A study of recombination centres in electron irradiated silicon solar cells.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Firstly the basic principles involved in the generation and recombination of electron-hole pairs is reviewed and the physics of particle irradiation is discussed. The properties of shallow and deep levels are also discussed and these deep level defects are then examined in detail. The characterisation technique known as Deep Level Transient Spectroscopy (DLTS) and some related techniques are then reviewed and the silicon solar cells used for this investigation are described.
The electrical properties of silicon solar cells doped with either boron, gallium, indium, aluminium or phosphorus formed on a variety of substrates are then determined before and after electron irradiation. The reduction in minority-carrier diffusion length caused by particle irradiation is deduced from these results by fitting the experimental data to a theoretical model. DLTS is then used to identify and categorise the deep levels present in these samples after particle irradiation. A new version of the forward bias DLTS technique is then defined and used to determine the minority-carrier capture cross-section of the positive charge state of the divacancy (VV+/0).
The Shockley-Read-Hall (SRH) model is then used to determine the minority-carrier lifetime of each of the observed defects in the gallium-doped cells. This model is then extended to show that the VV+/0 defect is mainly responsible for the lifetime degradation observed in irradiated czochralski silicon solar cells. The damage coefficients are then determined for all of the cells examined in this study and they were compared to the literature data. Finally it is shown that the commonly observed relationship between the doping density and damage coefficient in silicon solar cells can be explained simply in terms of the divacancies (VV+/0) capture cross-section, introduction rate, and its probability of occupation.
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Published date: 2002
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Local EPrints ID: 464827
URI: http://eprints.soton.ac.uk/id/eprint/464827
PURE UUID: 708acdea-b222-43e7-8e58-49dc6c519e37
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Date deposited: 05 Jul 2022 00:04
Last modified: 16 Mar 2024 19:46
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Author:
Robert Roland Smith
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