Optimal Semiconductors for 3H and 63Ni Betavoltaics

Betavoltaic power sources based on the conversion of radioisotope energy to electrical power are considered an appealing option for remote applications due to extended period of operation and high energy densities. However, to be competitive with other power sources, their efficiency must be increased. This can be done through optimization of the beta source and selection of the semiconductor absorber. This paper evaluates available on the market and developing wideband gap semiconductors as prospective absorbers with ³H and ⁶³Ni sources. Simulation results indicate that among wide band gap materials 4H-SiC and diamond are two optimal semiconductors due to the combination of good coupling efficiencies with isotope sources and good electronic transport properties. Additionally, having good coupling efficiency, an ultra-wide bandgap, and the capability for both n- and p-type doping, c-BN is a promising material for betavoltaic applications.