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Performance, Defect Behavior and Carrier Enhancement in Low Energy, Proton Irradiated p(+)nn(+) InP Solar CellsInP p(+)nn(+) cells, processed by MOCVD, were irradiated by 0.2 MeV protons and their performance and defect behavior observed to a maximum fluence of 10(exp 13)/sq cm. Their radiation induced degradation, over this fluence range, was considerably+less than observed for similarly irradiated, diffused junction n p InP cells. Significant degradation occurred in both the cell's emitter and base regions the least degradation occurring in the depletion region. A significant increase in series resistance occurs at the highest fluenc.e. Two majority carrier defect levels, E7 and E10, are observed by DLTS with activation energies at (E(sub C) - 0.39)eV and (E(sub C) - 0.74)eV respectively. The relative concentration of these defects differs considerably from that observed after 1 MeV electron irradiation. An increased carrier concentration in the cell's n-region was observed at the highest proton fluence, the change in carrier concentration being insignificant at the lower fluences. In agreement with previous results, for 1 and 1.5 MeV electron irradiated InP p(+)n junctions, the defect level E10 is attributed to a complex between zinc, diffused into the n-region from the zinc doped emitter, and a radiation induced defect. The latter is assumed to be either a phosphorus vacancy or interstitial. The increased, or enhanced carrier concentration is attributed to this complex acting as a donor.
Document ID
Document Type
Conference Paper
Weinberg, I. (NASA Lewis Research Center Cleveland, OH United States)
Rybicki, G. C. (NASA Lewis Research Center Cleveland, OH United States)
Vargas-Aburto, C. (Kent State Univ. OH United States)
Jain, R. K. (Toledo Univ. OH United States)
Scheiman, D. (NYMA, Inc. Brook Park, OH United States)
Date Acquired
August 19, 2013
Publication Date
September 1, 1994
Publication Information
Publication: Proceedings of the 13th Space Photovoltaic Research and Technology Conference (SPRAT 13)
Subject Category
Energy Production and Conversion
Distribution Limits
Work of the US Gov. Public Use Permitted.
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