AlGaAs 55Fe X-ray radioisotope microbattery

摘要

This paper describes the performance of a fabricated prototype Al0.2Ga0.8As (55)Fe radioisotope microbattery photovoltaic cells over the temperature range -20 °C to 50?°C. Two 400?μm diameter p(+)-i-n(+) (3?μm i-layer) Al0.2Ga0.8As mesa photodiodes were used as conversion devices in a novel X-ray microbattery prototype. The changes of the key microbattery parameters were analysed in response to temperature: the open circuit voltage, the maximum output power and the internal conversion efficiency decreased when the temperature was increased. At -20 °C, an open circuit voltage and a maximum output power of 0.2?V and 0.04?pW, respectively, were measured per photodiode. The best internal conversion efficiency achieved for the fabricated prototype was only 0.95% at -20 °C.