High energy-density radioisotope micro power sources

A method of constructing a solid-state energy-density micro radioisotope power source device (10). In such embodiments, the method comprises depositing the pre-voltaic semiconductor composition (38A), comprising a semiconductor material and a radioisotope material, into a micro chamber (28) formed within a power source device body (14). The method additionally includes heating the body (14) to a temperature at which the pre-voltaic semiconductor composition (38A) will liquefy within the micro chamber (28) to provide a liquid state composite mixture (38B). Furthermore, the method includes cooling the body (14) and liquid state composite mixture (38B) such that liquid state composite mixture (38B) solidifies to provide a solid-state composite voltaic semiconductor (38), thereby providing the solid-state high energy-density micro radioisotope power source device (10).