Tritium-powered betacells based on Al/sub x/Ga/sub 1-x/As

The paper describes betavoltaic cells (BVC) based on A/sup 3/B/sup 5/ semiconductors. It is shown that wide band gap semiconductors such as AlGaAs ensure the efficient betavoltaic conversion of beta radiation from tritium and photovoltaic (PV) conversion of the light from tritium powered radioluminescent sources. Betavoltaic cells based on Al/sub x/Ga/sub 1-x/As with ultrathin (0.01-0.03 /spl mu/m) wide bandgap passivating window were developed. Output current densities as high as (0.75-1)10/sup -6/ A/cm/sup 2/, open circuit voltage of 0.65-0.93 V and maximum power output of 0.55 /spl mu/W/cm/sup 2/ were achieved in the betacells in a capsule with tritium gas. Specific output power of 335 nW/Ci is ensured in the battery based on green tritium lamps and developed PV cells.