There are many methods for converting the beta particle energy to electrical energy. Conversion of the beta particle energy to the electrical energy using semiconductors, is one of the important methods that can be used in radioisotopic batteries. In this work, a photo-betavoltaic semiconductor battery has been designed and constructed. The battery produce electric energy by converting photon energy from the sun or kinetic energy of beta particles. Doping process of silicon to fabrication of the p-i-n diode has been investigated. Thus, diffusion of dopants in 1000°C, SEM analysis, calculation of doping concentration, calculation of the diffusion depth and electric resistance of the doped silicon have been investigated. The measured betavoltaic current was 50 pA for a 58 μCi 90Sr/90Y. The photo-betavoltaic battery has been simulated by Monte-Carlo MCNP5 code and 45.2 pA electric current has been obtained. A fairly good agreement was observed between experimental and numerical results. Also, this battery is responds to visible light, sensitivity of which is comparable with the sun cells.