Thermoelectric properties of cuprous oxide by first-principles method

Band structure and thermoelectric properties of $$\hbox {Cu}_{2}\hbox {O}$$ from GGA and GGA+U approaches

“…For a complete description of transport coefficients, we need a reasonable value of the relaxation time (τ ). This is found from the available experimental data described in our earlier work [19]. We found τ = 6.13 × 10 −15 s and 2.47 × 10 −17 s at 300 and 500 K, respectively.…”

“…The plane wave cut-off parameter rgkmax was set to 8.5. Both the GGA and GGA+U calculations are performed at the lattice constant a = 4.28 Å as described in our earlier work [19]. In the GGA+U calculations, the Hubbard U eff parameter is U eff = U − J , where U and J are the screened Coulomb and exchange parameters [14].…”

“…In the GGA+U calculations, the Hubbard U eff parameter is U eff = U − J , where U and J are the screened Coulomb and exchange parameters [14]. Several combinations of U and J were tried and the optimum values of the lattice constant, bulk modulus and band gap were found for U eff = 8 eV [19]. The U parameters considered by other workers [21] in the GGA (PBE)+U calculations alter the lattice constant merely by 1.2%.…”

“…We have also included the scissor correction in the TE coefficients computed from the band structures using GGA and GGA+U approaches. The scissor correction corrects for the difference in the calculated and measured values of the band gap [9,16,19]. We have calculated the EFF incorporating the scissor correction in the two sets of calculations.…”

“…It is very useful to see the utility of a semiconductor as the TE material. In this extended work, we give the electronic band structures and use the transport coefficients to evaluate EFF and its variation with carrier concentration [19]. EFF is compared with other similar compounds and a few most promising TE materials.…”