METHOD OF MAKING A THULIUM-171 DOPED BETAVOLTAIC BATTERY USING ERBIUM DOPANTS

Betavoltaic batteries and methods of making the same are provided. In embodiments, a method of making a thulium-171 electrically active betavoltaic battery includes: providing a starting semiconductor including a semiconductor material layer doped with a stable non-radioactive isotope erbium-170; irradiating the starting semiconductor with thermal neutrons, thereby causing conversion of at least a portion of the stable non-radioactive isotope erbium-170 to a radioisotope erbium-171, resulting in an intermediate semiconductor; and holding the intermediate semiconductor in a radiation safe environment for a period of time necessary for a predetermined amount of the erbium-171 to transform to a radionuclide thulium-171 via natural beta decay, thereby resulting in a final semiconductor, wherein the semiconductor material layer acts as both an electron emitter and an electron absorber simultaneously.