Tritium power supply sources based on AlGaAs/GaAs heterostructures

The results of the development of a radioisotope power supply source based on a semiconductor (Al$_{x}$Ga$_{1-x}$As/GaAs) $\beta$-radiation energy converter and tritium as a radiation source are presented. The efficiency of this converter with a tritium saturated titanium disk, a green luminescent tritium lamp, or tritium gas as a radioisotope radiation source is compared. For a converter based on the Al$_{0.35}$Ga$_{0.65}$As/GaAs heterostructure in a capsule with tritium, efficiency $\eta$ = 5.9% at a maximum specific output electrical power of 0.56 $\mu$W/cm$^2$. Due to their long service life, such stand-alone and compact power supply sources can be used in space and subsea technologies, implantable cardiac pacemakers, biosensors, and portable equipment of high reliability.