Performance optimization and temperature effects of 63Ni/Si-based PN and PIN junction betavoltaic batteries

Abstract

This study explores the performance optimization and temperature effect of betavoltaic batteries based on 63Ni radioactive sources and silicon materials in PN and PIN junctions. Through the Monte Carlo method simulations and multiphysics coupling modeling using COMSOL Multiphysics code, the doping concentrations and thickness of each layer in the two types of batteries are optimized. Furthermore, the synergistic temperature effects on the bandgap, carrier mobility, carrier lifetime, and effective density of states in silicon materials are comprehensively considered, and then the performance of batteries are analyzed. Results show that, compared with the PN betavoltaic battery irradiated by the same 63Ni source at 290 K, the PIN betavoltaic battery demonstrates significant performance advantages, including the short-circuit current density (Jsc) and maximum power density (Pmax) increase by 13.59% and 12.16%, respectively. Then, within the temperature range of 170–370 K, the open-circuit voltage (Voc) and Pmax of both types of batteries decrease linearly with temperature increasing, in which the open-circuit voltage sensitivity of the PN and PIN junction betavoltaic batteries is −3.05 and −3.03 mV/K, respectively, and the maximum output power density sensitivity is −0.60 and −0.68 nW/cm2/K, respectively. Therefore, the impact of temperature on Si should be considered as comprehensively as possible to ensure the reliability of the results in Si-based batteries. This study provides new insights for the optimal design of micro-betavoltaic batteries and the development of self-powered energy devices for applications such as temperature sensors.