THEORETICAL EVALUATION AND OPTIMIZATION OF THE RADIATION-RESISTANCE OF GALLIUM-ARSENIDE SOAR-CELL STRUCTURES

Theoretical treatments are used to analyze the performance of Ga 1-xAlxAs/GaAs heteroface and graded band-gap solar cells, and to study the radiation resistance of the two types of cell. The optimization of these solar-cell structures to tolerate radiation-induced degradation in electronic properties is discussed and their power-conversion efficiency evaluated. The calculations indicate only a marginally greater output from the graded band-gap cell compared to the conventional heteroface type for optimized structures. A comparison with the performance of a Si space cell under 1-MeV-electron irradiation is made which illustrates a superior performance from GaAs in respect of efficiency and radiation tolerance.