Radiation-Hard and Ultralightweight Polycrystalline Cadmium Telluride Thin-Film Solar Cells for Space Applications

Abstract

Achieving high-specific-power and radiation hardness of solar cells is of great importance to perform tasks and achieve duration in space. Therefore, we investigated the proton irradiation resistance of ultralightweight CdS/CdTe thin film solar cells having high specific power values. High-energy proton beams (15 MeV) with doses ranging from 1 X 10(12) to 1 X 10(15) cm(-2) were used, equivalent to more than 2000 years in low Earth orbit. Although 70% decrease in cell conversion efficiency was observed after proton irradiation with dose of 1 X 10(15) cm(-2), it still maintained the photovoltaic performance. The specific power of the fabricated cell decreased from 358 Wkg(-1) to 109 Wkg(-1) after proton irradiation (dose = 1 X 10(15) cm(-2)), which is still comparable to specific powers of other types of solar cells. Our work indicated that reduction of short circuit current is a major factor of deterioration of the cell performance under the high energy proton irradiation. This work revealed that our lightweight CdS/CdTe solar cells have significant potential for the use in space applications: reduction of launch cost by achieving high specific power and assurance of durability over prolonged space missions.