Betavoltaic Generation Function in Silicon

Betavoltaics refers to direct conversion of radioactive beta-decay energy into electricity. This effect is rather close to photovoltaics both in underlying physics and mathematical modeling. In the present contribution, the electronhole pair correlation function in silicon by beta-electrons of energy <; 30 keV is obtained theoretically. A good agreement of our results with the experimental findings is demonstrated. The scattering of beta-particles of different energies and their electron-hole pair generation function depending on the angle of entrance into the sample are analysed. An accurate analytical approximation for the electron-hole pair generation function in silicon coupled to a tritium beta-source is shown to be given by a stretched exponential expression instead of the simple Beer-Lambert law.