Enhanced thermoelectric properties of penta-graphene by strain effects process

Using the Boltzmann theory and first-principles electronic structure calculations, we investigated the thermal transport of penta-graphene (PG) without and with biaxial tensile strain effects. The results show that PG has desirable features of good thermoelectric. We predict that the carrier relaxation time of hole is longer than that of electron, implying better thermoelectric performance of p-type PG. The Seebeck coefficient of penta-graphene is 36 times as large as graphene, which is attributed to the existence of bandgap in the PG. In addition, the thermoelectric figure of merit (ZT) of PG is obtained, with optimized value (about 0.053) at room temperature, which is 5.9 times much higher than that of graphene. Moreover, we show that tensile strain effects on the thermoelectric properties of PG. It is found that tensile strain can induce significantly enhanced n- and p-type power factors. Extremely prominent, at room temperature, the ZT of p-type PG at the strain of 11% is 0.481, which is 9.1 times higher than that of unstrained one. The calculated results show that tensile strain is indeed a very effective strategy to achieve enhanced thermoelectric properties.