Abstract: The present disclosure relates to illumination devices and methods of generating light for extended periods of time without requiring an outside source of power, recharging, refueling or maintenance. The devices of the present disclosure comprise a plurality of quantum dots and a radioisotope, and may be used in numerous ways, for example, for the marking critical areas or paths, for the illumination of pathways in aircraft, ships, trains, buildings, and other facilities where these routes must be precisely delineated or identified for safety reasons, for the inclusion of signs or other indicia that must be illuminated at all times, as well as many military uses, such as for the demarcation of temporary airfields for fixed-wing aircraft or helicopters or for IFF (identification friend or foe).