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

Abstract

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.

Keywords

• betavoltaic battery
• 32Si
• DFT
• time-related properties
• β decay