Analyses of time-related performance of betavoltaic batteries using TiT2

Abstract

The time effect of tritium silicon p-n junction betavoltaic batteries is considered in this work. For a titanium tritium (TiT2) source, the processes of decaying, tritium leaking, swelling and 3He releasing are contained in the calculation, and expressions of component and density changes are obtained. As time goes by, the self-absorption rate has a downward trend, while all electrical performances decrease, especially the short-circuit current (ISC ) and the maximum output power (Pmax ). At about 3.5 a, the battery begins to release gaseous 3He, and the expiry date of the battery is about 10.7 a, shorter than the half-life of tritium. The result indicated that for a tritium source, the time leads to a significant reduction in the electrical performance of the battery, which cannot be ignored in simulations and experiments.