Structure and thermoelectric performance of layered compounds Nd1−xSrxOZnSb

Layered compound NdOZnSb is isostructural to ZrSiCuAs with insulating [NdO] layers and conductive [ZnSb] layers alternatively stacked along the c axis. As a narrow band-gap p-type semiconductor, NdOZnSb has lower electrical conductivity, resulting in poor thermoelectric performance despite considerably high Seebeck coefficient and low thermal conductivity. Polycrystalline samples Nd1−xSrxOZnSb have been prepared with the aim to increase the hole concentration and improve the electrical properties via p-type doping. It is found that the electrical conductivity increases almost 9 times with 7% Sr concentration in comparison to the undoped sample at 325 K. Thus, the thermoelectric figure of merit has been improved significantly.