Liquid-semiconductor-based micro power source using radioisotope energy conversion

In this paper, we present a betavoltaic micro power source using liquid-semiconductor for the first time. We have fabricated and characterized a MEMS-based micro battery, which is powered by a radioactive source with a liquid-semiconductor-based Schottky diode. Semiconductor properties of liquid selenium are utilized with radioactive sulfur (
³⁵
S) for direct power conversion. The radioisotope material is encapsulated with liquid semiconductor in a micromachined device. Experimental results show that maximum of 16.2 nW can be harvested from the micromachined liquid semiconductor Schottky diode. A large open-circuit voltage of 899 mV and short-circuit current of 0.107 muA were also observed.