Semiconductor betavoltaic batteries with p-n diodes

A method of making an electrically inactive betavoltaic battery device comprising:

• fabricating a p-n diode comprising a p-type semiconductor layer including at least one stable isotope that transforms into at least one beta-particle emitter upon irradiation with thermal neutrons, and an n-type semiconductor beta-particle absorber layer configured to absorb beta particles.

A method of making an electrically active betavoltaic battery comprising:

• providing an electrically inactive betavoltaic battery device comprising a p-type semiconductor layer including at least one stable isotope that transforms into at least one beta-particle emitter upon irradiation with thermal neutrons, and an n-type semiconductor beta-particle absorber layer configured to absorb beta particles, wherein the p-type semiconductor layer and the n-type semiconductor beta-particle absorber layer form a p-n diode;
• and
• irradiating the electrically inactive betavoltaic battery device with thermal neutrons, thereby causing the conversion of at least a portion of the at least one stable isotope to a radionuclide and creating the electrically active betavoltaic battery.