Lattice thermal conductivity and thermoelectric properties of two-dimensional honeycomb monolayer of CdO

The lattice thermal conductivity of the CdO monolayer was investigated by density functional theory in combination with Boltzmann transport theory and it was estimated about 3.346 Wm- 1K-1 at T = 300 K. Comparing this result with the one reported for the bulk CdO, it was revealed that the lattice thermal conductivity of the monolayer is lower than the bulk CdO. The lower lattice thermal conductivity of the CdO monolayer was attributed to the lower phonon lifetime and phonon group velocity in comparison to the bulk counterpart. Considering the lower lattice thermal conductivity of the monolayer, higher thermoelectric efficiency was estimated in comparison with the reported efficiency for the bulk CdO. At T = 900 K, the maximum zT = 0.76 can be found in p-type for the hole concentrations of 7.2 x 1012 cm-2.