Exceptional Thermoelectric Performance Enabled by High Carrier Mobility and Intrinsically Low Lattice Thermal Conductivity in Phosphide Cd<sub>3</sub>P<sub>2</sub>
Lizhu Fan, Kunling Peng, Zizhen Zhou, Yanci Yan, Ran Chen, Honghui Wang, Guang Han, Bin Zhang, Xu Lu, Guoyu Wang, Xiaoyuan Zhou
Abstract
A novel thermoelectric Cd3P2 is obtained via regulating carrier concentrations. Ultrahigh carrier mobilities over 1500 cm2 V–1 s–1 are observed at room temperature, which is attributed to small band effective mass and confirmed by the electronic structure calculation. Meanwhile, the intrinsically low lattice thermal conductivity below 1.0 W m–1 K–1 in the investigated temperature range is found due to the complex crystal structure and low sound velocity. Combined with high mobility and low thermal conductivity, a peak zT of 0.91 at 673 K and an excellent average zT of 0.57 over 300–673 K are obtained in Cd3P2-based compounds, which are record-high values among phosphides. This study highlights the potential of exploring high-performance novel thermoelectric materials in compounds with high carrier mobility.