Analysis (Simulation) of Ni-63 beta-voltaic cells based on silicon solar cells

Beta-voltaic cells based on standard silicon solar cells with bilateral coating with beta-radiation sources in the form of $^{63}$Ni isotope have been studied experimentally and by numerical simulation. The optimal parameters of the cell, including its thickness, the doping level of the substrate, the depth of the $p$–$n$ junction on its front side, and the $p^+$ layer on the back side, as well as the activity of the source material, have been calculated. The limiting theoretical values of the open-circuit voltage (0.26 V), short-circuiting current (2.1 $\mu$A), the output power of the cell (0.39 $\mu$W), and the efficiency of the conversion of the radioactive energy onto the electric energy (4.8%) have been determined for a beta-source activity of 40 mCi. The results of numerical analysis have been compared with the experimental data.