Abstract: A thermoelectric element to convert thermal energy into electrical energy includes a first electrode part, a second electrode part having a different work function than the first electrode part and arranged at a distance from the first electrode part, on a same surface of a substrate as the first electrode part, and a middle part provided between the first electrode part and the second electrode part.

Abstract: A lighting device includes a light-emitting device, a heat sink having a hollow unit inside, a translucent cover, and a thermoelectric element. The thermoelectric element includes a casing unit having a housing unit, and includes a first electrode unit, a second electrode unit having a work function different from that of the first electrode unit, and a middle unit including nanoparticles having a work function between the work function of the first electrode unit and the work function of the second electrode unit, which are provided inside the housing unit. The casing unit is provided on the inner surface of the hollow unit of the heat sink.

Abstract: A light-emitting device with an electric power generation function includes a thermal conductive LED board that includes a thermal conductive base having a mounting surface and an open surface, and a board wiring provided on the mounting surface. An LED element is connected with the board wiring. A thermoelectric element is electrically insulated from the thermal conductive base, and thermally coupled with the thermal conductive base. The thermoelectric element includes a casing unit having a housing unit, and includes, in the housing unit, a first electrode unit, a second electrode unit having a work function different from a work function of the first electrode unit, and a middle unit including nanoparticles having a work function between the work function of the first electrode unit and the work function of the second electrode unit. The casing unit is provided on the open surface of the thermal conductive base.

Abstract: A lighting device includes a light-emitting device, a heat sink having a hollow unit inside, a translucent cover, and a thermoelectric element. The thermoelectric element includes a casing unit having a housing unit, and includes a first electrode unit, a second electrode unit having a work function different from that of the first electrode unit, and a middle unit including nanoparticles having a work function between the work function of the first electrode unit and the work function of the second electrode unit, which are provided inside the housing unit. The casing unit is provided on the inner surface of the hollow unit of the heat sink.

Abstract: A thermoelectric element to convert thermal energy into electrical energy includes a first electrode part, a second electrode part having a different work function than the first electrode part and arranged at a distance from the first electrode part, on a same surface of a substrate as the first electrode part, and a middle part provided between the first electrode part and the second electrode part.