Ultra-low lattice thermal conductivity and high thermoelectric efficiency of K3AuO

Based on the combination of first-principles calculations and Boltzmann transport equation, we investigated the thermal transport properties of K 3AuO and predicted a figure of merit ZT = 2.01 at 700 K with p-type doping. Such a high thermoelectric efficiency can be attributed to the ultra-low lattice thermal conductivity with a value of 0.48 Wm − 1 K − 1 at 300 K, and detailed research shows that the low lattice thermal conductivity arises from the small phonon group velocity and high scattering rates; moreover, the figure of merit ZT of p-type doped K 3AuO can be maintained at around 2 in a relatively wide carrier concentration of 5.5 × 10 20– 1.2 × 10 21 cm − 3, which demonstrates the stable thermoelectric properties of K 3AuO.