Tritiated Amorphous Silicon Betavoltaic Devices

The introduction of tritium into hydrogenated amorphous silicon has given rise to a novel material with interesting physical properties and potential applications. Tritium undergoes radioactive decay, transforming into ³He⁺ and emitting an electron with average energy 5.7 keV, at a rate equivalent to a half-life of 12.3 years. The decay of tritium results in the creation of electron-hole pairs and in the formation of dangling bonds. Infrared spectroscopy and effusion measurements were used to analyse tritium bonding in the silicon network. Electron spin resonance and photoluminescence of tritiated amorphous silicon were examined as a function of time to study the evolution of dangling bonds. Thermal annealing was used to study metastability of dangling bonds in the material. Electrical characteristics of pin diodes containing tritium in the intrinsic layer were investigated. The application of tritiated-hydrogenated amorphous silicon in betavoltaic devices is presented.