  thermoelectric materials show the thermoelectric effect in a strong or convenient form. the thermoelectric effect refers to phenomena by which either a temperature difference creates an electric potential or an electric potential creates a temperature difference. these phenomena are known more specifically as the seebeck effect (converting temperature to current), peltier effect (converting current to temperature), and thomson effect (conductor heating/cooling). while all materials have a nonzero thermoelectric effect, in most materials it is too small to be useful. however, low-cost materials that have a sufficiently strong thermoelectric effect (and other required properties) could be used in applications including power generation and refrigeration. a commonly used thermoelectric material in such applications is bismuth telluride ().  ==applications== ===power generation===  approximately 90% of the worldâs electricity is generated by heat energy, typically operating at 30â40% efficiency, losing roughly 15 terawatts of power in the form of heat to the environment. thermoelectric devices could convert some of this waste heat into useful electricity. thermoelectric efficiency depends on the figure of merit, zt. there is no theoretical upper limit to zt, and as zt approaches infinity, the thermoelectric efficiency approaches the carnot limit. however, no known thermoelectrics have a zt>3. as of 2010, thermoelectric generators serve application niches where efficiency and cost are less important than reliability, light weight, and small size. internal combustion e
Materials_science Thermoelectricity