New member of micro power sources for extreme environmental explorations: X-ray-voltaic batteries

It has been a long-term challenge for radiation-voltaics to meet the power requirements of the fast-developed exploration activities in extreme environments such as deep sea, polar regions, and outer space. In this work, we demonstrated novel X-ray radiation-voltaic (X-ray-voltaic) batteries adopting SiC conversion units, which could improve the output power up to 3 orders of magnitude higher than that of state-of-the-art betavoltaics. A comprehensive model integrating the radioactive sources and semiconductor units was built to guide the design of X-ray voltaics. SiC devices with the optimal structure were fabricated and confirmed experimentally the ac-curacy of the device model. According to the model, the SiC X-ray-voltaics with 55Fe radioactive sources can achieve a highest output power of 19.10 mu W/cm2 and a highest power efficiency (eta total) of 7.71%. The unique advantages of SiC X-ray-voltaic batteries including the excellent irradiation hardness, the superlong lifetime, and the outstanding prospects as power sources were discussed in details. This work reveals the promising potentials of the X-ray-voltaics for extreme environmental explorations and will inspire the further development of the high-performance isotope batteries.