Thermoelectric properties of CuCrSe[sub 2] (original) (raw)

The efficient conversion of heat into electricity using a thermoelectric approach requires high performance materials with the thermoelectric figure of merit ZT $ 1. Here we report on bulk CuCrSe 2 , which exhibits a very high ZT $ 1 at 773 K. The titled compound exhibits an electrical resistivity of 2.8mUcm,aSeebeckcoefficientof2.8 mU cm, a Seebeck coefficient of 2.8mUcm,aSeebeckcoefficientof160 mV K À1 , together with very low thermal conductivity $7 mW cm À1 K À1 at 773 K. The very low thermal conductivity of bulk CuCrSe 2 is attributed to phonon scattering by various sources such as (i) superionic Cu ions between the CrSe 2 layers, (ii) nanoscale precipitates in the bulk and (iii) natural grain boundaries due to the layered structure of the material. This unusual combination of thermoelectric properties for CuCrSe 2 suggests that it is an ideal example of the phonon glass and electron crystal approach.