Title :
Radiation effects in Ga0.47In0.53As devices
Author :
Walters, R.J. ; Shaw, G.J. ; Summers, G.P. ; Burke, E.A. ; Messenger, S.R.
Author_Institution :
US Naval Res. Lab., Washington, DC, USA
fDate :
12/1/1992 12:00:00 AM
Abstract :
The effects of irradiating Ga0.47In0.53As solar cells and p-i-n photodiodes with 1-MeV electrons were measured using deep level transient spectroscopy (DLTS) and both dark and illuminated (1 sun, air mass zero (AM0)) I-V measurements. Fits of the dark I-V data to the two-term diode equation before irradiation were satisfactory, yielding an estimated bandgap energy of 0.79 eV. The DLTS detected two radiation-induced defect levels, one shallow (0.10 eV) and one near mid-gap (0.29 eV). Temperature coefficients of the Ga0.47In 0.53As photovoltaic parameters follow the same general behavior as for other solar cell materials (e.g., Si and GaAs). However, a sharp decrease in the short circuit current is observed above ≈375 K. This temperature is reduced by irradiation. Isochronal thermal annealing induced recovery in the photovoltaic parameters at ≈400 K, coinciding with an annealing stage of the near mid-gap defect level
Keywords :
III-V semiconductors; annealing; deep level transient spectroscopy; defect electron energy states; electron beam effects; gallium arsenide; indium compounds; p-i-n photodiodes; short-circuit currents; solar cells; 1 MeV; 100 to 450 K; DLTS; Ga0.47In0.53As devices; bandgap energy; dark I-V characteristics; deep level transient spectroscopy; electron irradiation; illuminated I-V characteristics; isochronal annealing; near mid-gap defect level; p-i-n photodiodes; photovoltaic parameters; radiation-induced defect levels; short circuit current; solar cells; two-term diode equation; Annealing; Electrons; Mass spectroscopy; PIN photodiodes; Photovoltaic cells; Photovoltaic systems; Radiation effects; Solar power generation; Sun; Temperature;
Journal_Title :
Nuclear Science, IEEE Transactions on
