Transport properties of 2D As1-xPx binary compounds as a potential thermoelectric materials

Using the electronic band structure of the optimized monolayer and bilayer As_1-xP_x structure calculated through the DFT calculation a comprehensive study on the electronic transport properties based on the Boltzmann transport theory are investigated within the respect of the constant relaxation time approximation τ. The Seebeck coefficient of the monolayer As_xP_1-x system has a larger value than the bilayer system and shows no anisotropic behavior along the armchair and zigzag directions while we found a higher electrical conductivity along the armchair direction in both mono and bilayer structures. A similar behavior was found in the electronic contribution to the thermal conductivity and this was understood from the Weidmann–Franz law. We also found that the power factor had a larger value along the armchair direction than the zigzag direction. Besides, in monolayer system, the p-type As_0.75P_0.25 alloy showed a highest power factor while the n-type bilayer As_0.75P_0.25 alloy system displayed a highest power factor. Thus, we suggest that the thermoelectric property can be improved in alloy system compared with the pristine phosphorene and arsenene layer.