Ab initio study of electrical and thermal properties of dithino-naphtridine isomer for meta-meta linking

The present study uses density functional theory (DFT) and non-equilibrium Green’s function (NEGF) to investigate the transmission coefficient T (E) for dithino-naphtridine molecules with different positions of side group oxygen atoms. The electric conductance calculation shows that the bare molecule has a higher conductance than the molecules with oxygen dangling, which varied from-4.7 to-5.5(eV), while the Seebeck coefficient (S) is found for all molecules with a positive sign with a higher value of 254 (µV/K) for molecules terminated by hydrogen around Fermi level EF = 0. Other thermal parameters are calculated, such as thermal conductance K which is found to change between 55 x10−15 for M_1and 4x10−15 (w/K.m) for M_3. Finally, the higher value of the figure of merit (ZT) is about 0.8 for molecule M_3.