An optical/electrical transducer device has housing, formed of a thermally conductive section and an optically transmissive member. The section and member are connected together to form a seal for a vapor tight chamber. Pressure within the chamber configures a working fluid to absorb heat during operation of the device, to vaporize at a relatively hot location as it absorbs heat, to transfer heat to and condense at a relatively cold location, and to return as a liquid to the relatively hot location. The transducer device also includes a wicking structure mounted within the chamber to facilitate flow of condensed liquid of the working fluid from the cold location to the hot location. At least a portion of the wicking structure comprises semiconductor nanowires, configured as part of an optical/electrical transducer within the chamber for emitting light through and/or driven by light received via the transmissive member.