Super thermoelectric power of one-dimensional TlInSe2

Seebeck coefficient of the structurally one-dimensional material, TlInSe2, known as a p-type conductor, has been measured in the temperature range 70 °C to 500 °C in vacuum by using four probe techniques. At temperatures above 200 °C this coefficient is found to be negative. With temperature down to below 200 °C, the coefficient is becoming positive and huge to a cutting-edge value of 107 μV/°C. The obtained results are discussed in terms of an incommensurate superlattice phase, which might have taken place in TlInSe2 at temperatures below 200 °C, and led to the above unique thermoelectric properties of this material. It is expected that thermoelectric devices based on TlInSe2 will have superior parameters.