초록 ▼

Transition metals of Group VIII (Co, Rh and Ir) have been prepared as semiconductor compounds with the general formula TSb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may

Transition metals of Group VIII (Co, Rh and Ir) have been prepared as semiconductor compounds with the general formula TSb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using vertical gradient freezing techniques and/or liquid phase sintering techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities (up to 1200 cm.sup.2.V.sup.-1.s.sup.-1) and good Seebeck coefficients (up to 150 .mu.VK.sup.-1 between 300.degree. C. and 700.degree. C.). Optimizing the transport properties of semiconductor materials prepared from elemental mixtures Co, Rh, Ir and Sb resulted in a substantial increase in the thermoelectric figure of merit (ZT) at temperatures as high as 400.degree. C. for thermoelectric elements fabricated from such semiconductor materials.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus using a gradient freeze technique to prepare a semiconductor alloy for use in fabricating thermoelectric elements comprising:a furnace defined in part by a housing having a chamber with a first heater and a second heater disposed therein;the first heater disp

[ What is claimed is:] [1.] An apparatus using a gradient freeze technique to prepare a semiconductor alloy for use in fabricating thermoelectric elements comprising:a furnace defined in part by a housing having a chamber with a first heater and a second heater disposed therein;the first heater disposed within the chamber above the second heater;a thermal baffle disposed within the chamber between the first heater and the second heater;a container disposed within the chamber with the container adjacent to the thermal baffle;the container sealed with a vacuum formed therein;a rod vertically disposed within the chamber and the container secured to one end of the rod; anda plurality of elemental materials selected from the group comprising Co, Rh, Ir and Sb disposed within the container for melting within the furnace to form the semiconductor alloy.