Theoretical Prediction of Diamond Betavoltaic Batteries Performance Using ^63Ni

A diamond p-n junction is used to convert the decay energy of ^63Ni source into electrical energy. The self-absorption effect of the ^63Ni source, the backscatter process and the transport process of beta particles in diamond materials are studied. Then the theoretical maximum of electrical properties and the energy conversion efficiencies of diamond-^63Ni p-n junction batteries are achieved. Finally, a feasible design of p^+p^-n^+ junction battery, which has the maximum output power density of 0.42 \muW/cm^2 and the optimal device conversion efficiency of 26.8%, is proposed.