A thermoelectric conversion element includes a P-type thermoelectric conversion layer, a first metal layer, a second metal layer, a first joining layer, and a second joining layer. The P-type thermoelectric conversion layer includes a thermoelectric conversion material containing Mg and at least one selected from the group consisting of Sb and Bi. The first metal layer and the second metal layer each include Cu or a Cu alloy. The first joining layer and the second joining layer each include Al or an Al alloy containing Mg.

An electrochemical cell comprises a first electrode having a first inner surface; a second electrode having a second inner surface, the second inner surface facing the first inner surface; a nanostructured material positioned on at least one of the first inner surface and second inner surface; and an ionic liquid positioned between the first inner surface and the second inner surface, the ionic liquid being in electrical communication with the first electrode and second electrode.

The present invention provides a thermoelectric material excellent in heat resistance with less degradation of thermoelectric characteristics even in a high temperature environment. The thermoelectric material comprises a compound represented by a chemical formula Mg.sub.2Si.sub.1-xSn.sub.x (0<x<1) wherein at least one of the Si site and the Sn site of the compound is replaced with at least one of Sb and Bi, and an added Fe.

The present invention provides a thermoelectric material excellent in heat resistance with less degradation of thermoelectric characteristics even in a high temperature environment. The thermoelectric material comprises a compound represented by a chemical formula Mg.sub.2Si.sub.1-xSn.sub.x (0<x<1) wherein at least one of the Si site and the Sn site of the compound is replaced with at least one of Sb and Bi, and an added Fe.

A thermionic energy converter, preferably including an anode and a cathode. An anode of a thermionic energy converter, preferably including an n-type semiconductor, one or more supplemental layers, and an electrical contact. A method for work function reduction and/or thermionic energy conversion, preferably including inputting thermal energy to a thermionic energy converter, illuminating an anode of the thermionic energy converter, thereby preferably reducing a work function of the anode, and extracting electrical power from the system.

An integrated circuit (IC) package comprising an IC die, the IC die having a first surface and an opposing second surface. The IC die comprises a semiconductor material. The first surface comprises an active layer. A thermoelectric cooler (TEC) comprising a thermoelectric material is embedded within the IC die between the first surface and the second surface and adjacent to the active layer. The TEC has an annular shape that is substantially parallel to the first and second surfaces of the IC die. The thermoelectric material is confined between an outer sidewall along an outer perimeter of the TEC and an inner sidewall along an inner perimeter of the TEC. The outer and inner sidewalls are substantially orthogonal to the first and second surfaces of the IC die.

An integrated circuit (IC) package comprising an IC die, the IC die having a first surface and an opposing second surface. The IC die comprises a semiconductor material. The first surface comprises an active layer. A thermoelectric cooler (TEC) comprising a thermoelectric material is embedded within the IC die between the first surface and the second surface and adjacent to the active layer. The TEC has an annular shape that is substantially parallel to the first and second surfaces of the IC die. The thermoelectric material is confined between an outer sidewall along an outer perimeter of the TEC and an inner sidewall along an inner perimeter of the TEC. The outer and inner sidewalls are substantially orthogonal to the first and second surfaces of the IC die.

A thermoelectric conversion material includes a base material that is a semiconductor having Si and Ge as constituent elements, a first additive element that is different from the constituent elements, has a vacant orbital in a d or f orbital located inside an outermost shell thereof, and forms a first additional level in a forbidden band of the base material, and oxygen. The oxygen content ratio is 6 at % or less.

A magnesium-based thermoelectric conversion material includes a first layer formed of Mg.sub.2Si and a second layer formed of Mg.sub.2Si.sub.xSn.sub.1-x (here, x is equal to or greater than 0 and less than 1), in which the first layer and the second layer are directly joined to each other, and within a junction surface with the first layer and in the vicinity of the junction surface, the second layer has a tin concentration transition region in which a tin concentration increases as a distance from the junction surface increases. The junction layer is regarded as a site in which a tin concentration is found to be equal to or lower than a detection limit by the measurement performed using EDX.

One embodiment discloses a thermoelectric element comprising: a first substrate; a plurality of thermoelectric legs disposed on the first substrate; a second substrate disposed on the plurality of thermoelectric legs above the first substrate; electrodes including a plurality of first electrodes disposed between the first substrate and the plurality of thermoelectric legs and a plurality of second electrodes disposed between the second substrate and the plurality of thermoelectric legs; and a first reinforcing part disposed on the lower surface and a portion of the side surface of the first substrate.