Diboron-porphyrin monolayer: A new 2D semiconductor

We investigate a new 2D semiconductor material with BC10N2 stoichiometry based on the molecular structure of diboron porphyrin. Ab-initio molecular dynamics simulations indicate mechanical stability for temperatures up to T=4000 K. Electronic structure calculations based on density functional theory predict a 0.6 eV direct band gap. We employ the Boltzmann transport equation within the relaxation time approximation to analyze electronic transport properties as a function of charge carrier density at room temperature. The lattice thermal conductivity at room temperature was obtained from non-equilibrium molecular dynamics simulations, and we found anisotropic conductivities given by 160 and 115 W/m·K along perpendicular in-plane directions. The thermoelectric figure of merit ZT calculated at 300 K has a maximum value of 0.008. This result indicates that, in spite of its interesting anisotropic transport properties, BC10N2 is not a suitable candidate for thermoelectric applications.