Analysis of radiation damaged and annealed gallium arsenide and indium phosphide solar cells using deep level transient spectroscopy.
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Authors
Bruening, Joseph A.
Subjects
Radiation damage in solar cells
DLTS
Annealing
Heterojunction
Gallium arsenide
Indium phosphide
DLTS
Annealing
Heterojunction
Gallium arsenide
Indium phosphide
Advisors
Michael, Sherif
Date of Issue
1993-09
Date
September 1993
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Power loss in spacecraft solar cells due to radiation damage was investigated. The mechanisms behind the degradation and based on deep-level defects in the crystalline lattice structure of the solar cell. Through a process known as Deep Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy of the cell. Gallium (GaAs/Ge) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation, to fluences of 1E16 electrons/sq cm. Attempts at recovery included thermal annealing, alone, and with an applied forward bias current, and injection annealing. Various cycles of irradiation, annealing and DLTS were performed, in an attempt to correlate damage to trap energy level and growth. The results show that DLTS cannot be performed on GaAs/Ge, and no recovery was apparent in these cells. DLTS analysis of InP indicated excellent photoinjection annealing recovery at a variety of temperatures. Lower energy level defects are associated with the recovery of the cells while the higher energy traps are indicative of permanent degradation in the Inp solar cells. Applying this information to future research could increase satellite mission life, and significantly reduce space mission costs.
Type
Thesis
Description
Series/Report No
Department
Department of Aeronautics and Astronautics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
119 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.