p-型层状氧化锌的热电性质研究

采用第一性原理和玻尔兹曼输运理论,我们系统的研究了p-型二层氧化锌的热电性质.基于对单层氧化锌的晶格优化,计算得到其无虚频的声子谱,证明了它的热力学稳定性.由此构建了热力学性质稳定的二层氧化锌.采用实空间有限差分法生成了二层氧化锌的二阶和三阶力常数,然后得到了其声子散射和晶格热导率,使用两种计算方法得到了其晶格热导率在室温下分别为κ_ι~(BTE)=2.65 W/m·K和κ_ι~(RTA)=2.38 W/m·K.并且得到了p-型二层氧化锌在300 K至900 K等差温度下的热电优值为0.052～0.601,证明通过调节温度可以获得较高的热电优值.

Study on thermoelectric properties of P-type two-layer zinc oxide

Using the first principle and Boltzmann transport theory, the thermoelectric properties of P-type two-layer zinc oxide have been systematically studied. Based on the lattice optimization of monolayer ZnO, the phonon spectrum without virtual frequency is calculated, and its thermodynamic stability is proved. Thus, two-layer zinc oxide with thermodynamically stable properties are constructed. The second and third order force constants of two-layer zinc oxide are generated by real space finite-difference method, and then the phonon scattering and lattice thermal conductivity are obtained. The lattice thermal conductivity is obtained by two calculation methods at room temperature. In addition, the thermoelectric optimum value of P-type two-layer zinc oxide at 300K to 900K isothermal temperature is 0.052~0.601, which proves that a higher thermoelectric optimum value can be obtained by adjusting the temperature.