First principles study on the time-related properties of 4H-³²SiC as an energy converting material of betavoltaic batteries

The radioactive 4H- 32 SiC is applied as an energy converting material to fabricate high performance betavoltaic batteries. The time-related component change is considered, and the structural, stability and electrical property changes are calculated by density functional theory. As time goes by, the number of 32 Si atoms decrease exponentially while the concentration of 32 S increases gradually. The Si 63 PC 64 configurations have smaller lattice constants, while the lattices of Si 62 PSC 64 configurations are larger. All Si 63 PC 64 and Si 62 PSC 64 configurations have very small bandgaps indicating the metallic behavior. This suggests that the betavoltaic battery with 4H- 32 SiC is likely to transform into a Schottky diode over time.