Photovoltaic properties of an AlxGa1−xAs solar cell (x=0–0.22) grown on Si substrate by metalorganic chemical vapor deposition and thermal cycle annealing

The effects of a thermal cycle annealing (TCA) process on the defects in GaAs and AlxGa1−xAs solar cells on Si substrates are described in this paper. The defect density is reduced and the solar cell efficiency is improved by TCA. The defect density and the solar cell efficiency are evaluated in detail with respect to TCA temperature and Al composition. The problems involved in the fabrication of a high efficiency AlGaAs solar cell on a Si substrate are discussed.