Epitaxial layer to boost betavoltaic performance in SiC Schottky diodes

Betavoltaic cells harness the decay of beta-radiation to directly generate electrical power—making them of interest for powering remote or isolated devices. Compound semiconductors are promising materials for use in advanced betavoltaic cells owing to their excellent electronic properties combined with radiation hardness. Modifying the device architecture is one way the electrical power generated from absorbed incoming beta-radiation can be enhanced. In this study, an epitaxial layer is added to a SiC Schottky diode to create a betavoltaic device with greater power output. This output is quantified using simulated beta radiation (electron beam-induced current) and beta radiation from either a 63Ni or a 90Sr/90Y emitter. The epitaxial layer-related enhancement increases as the energy of the incoming simulated radiation increases, which is confirmed in practice for the 90Sr/90Y exposed device having Voc = 0.37 V, Jsc = 0.054 μA/cm2, and Pmax = 0.014 W/cm2.