The Study On The Thermoelectric Properties Of Penta-grapene

Science and technology is the first productive force, with the development of science and technology more and more by-products generate increasingly side influences on our daily life and environment. The development of science and technology cause the consumption of non-renewable energy, in addition to increasing the energy crisis, our environment is adversely effected. To mitigate these crises, we need to develop more environmentally friendly and more efficient renewable energy. Our subject, thermoelectric material is an outstanding environmental protection material to meet the above requirements. And improve the efficiency of the thermoelectric materials and looking for efficient thermoelectric materials has become top priority in the study of material scientists.In recent years, a new type of material, penta-graphene caught our attention. Not only because of its stability characteristics, has it also had very excellent thermoelectric potential. The thermoelectric properties of the materials is mainly characterized by the figure of merit of the materials, the defined formula is = 2/(+ ), and S is the Seebeck coefficient, σ represent the electrical conductivity of material, T is the absolute temperature of the environment, and is the electronic thermal conductivity and the lattice thermal conductivity of materials, respectively. For different materials, the higher the value of ZT is the thermoelectric performance is better.First of all, we calculated the band structure of penta-graphene using first-principle and the density theory. We observed that penta-graphene is an indirect band gap semiconductor. But the difference between the highest point and the second highest point of the valence band is very small; the penta-graphene can also be classified as direct band gap semiconductor. This is the reason why penta-graphene has some advantages of indirect band gap semiconductor and has some outstanding characteristics of direct band gap semiconductor as well. Moreover, we also calculated the density of states of penta-graphene, observing the density of states curve we found that the density of states around Fermi level shows a higher peak. After analysis the PDOS of the sp2 hybridization C2 atom and the sp3 hybridization C1 atom, we know that the peak in the total density of states is mainly contributed by the Pz orbital electron of C2 atom. After that we calculated the thermoelectric properties of penta-graphene by Boltz Tra P package. We realized that penta-graphene is a p-type semiconductor with the peak of Seebeck coefficient of penta-graphene is much higher than graphene and graphdiyne, which imply that penta-graphene does have the potential to become a very ideal thermoelectric material. After that we calculated the density of states and the band structure of penta-graphene under pressure, found that pressure does not have an obvious impact on the performance of penta-graphene. At last, we summarized the Seebeck coefficient and the relationship between electronic power factor with the carrier concentration of penta-graphene under different pressures in 400 K, only to find that the pressure does not have a significant impact on the thermoelectric properties of penta-graphene. These calculations on pressures illustrate the penta-graphene is very stable under pressure, which reflects that penta-graphene can still act as an excellent thermoelectric material in the environment with pressure.