论文标题
拓扑分层的N型热电学基于Bismuth telluride固体溶液
Topological layered n-type thermoelectrics based on bismuth telluride solid solutions
论文作者
论文摘要
基于$ bi_ {2} te_ {3} $的拓扑n型热电学，带有原子替代品bi $ \ rightarrow $ in，te $ \ rightarrow $ se，s，s，s，s，形态和dirac fermions的表面状态（van der waals in van der waals in scanning/scanning the scanning the niring the niring the niring the n the nim the nim perfecre）技术。通过STM方法，发现了表面上的深色和光斑，强度取决于固体溶液的组成和热电特性。固体溶液中观察到的表面形态特征是由表面电子状态的扭曲来解释的，该表面是由原子取代，掺杂杂质的影响以及结构缺陷的形成。 （0001）表面的形态STM图像的快速傅立叶变换（FFT）用于获得由缺陷引起的表面电子散射引起的准粒子激发的干扰模式。 DIRAC点能量及其波动，表面缺陷的峰值能量，价和导带边缘的位置以及能量间隙从隧道光谱的分析中确定。发现了狄拉克费米斯表面态的参数与热电特性之间的相关性。因此，在具有高功率因数的固体溶液中表面浓度的上升，Fermions表面状态的贡献增加，并且在$ BI_ {1.98} IN_ {0.02} TE_ {2.85} se_ {0.15} se_ {0.15} $组成中观察到了最大的浓度值。费米能量对不同固体溶液的依赖性由一组狄拉克锥体切片来描述，这些圆锥锥体在dirac点能量的波动的范围内近在咫尺，这是由Fermi速度的弱变化在研究的theruride terrinuride sublattices中的原子替代品中的fermi速度变化所解释的。
In topological n-type thermoelectrics based on $Bi_{2}Te_{3}$ with atomic substitutions Bi $\rightarrow$ In, Te $\rightarrow$ Se, S, the morphology and the surface states of Dirac fermions on the interlayer (0001) surface of van der Waals were studied by scanning tunneling microscopy and spectroscopy (STM/STS) techniques. By the STM method, the dark and light spots on the surface were found, which intensities depend on the composition and thermoelectric properties of solid solutions. The observed surface morphology features in the solid solutions are explained by distortions of surface electronic states originated by atomic substitutions, influence of doping impurity, and formation of structural defects. Fast Fourier transform (FFT) of the morphology STM images of the (0001) surface were used to obtain the interference patterns of the quasiparticles excitation caused by surface electrons scattering by defects. The Dirac point energy and its fluctuations, peak energies of surface defects, the positions of the valence and conduction band edges, and the energy gap were determined from an analysis of tunneling spectra. A correlation between the parameters of surface states of Dirac fermions and thermoelectric properties was found. Thus, a contribution of the fermions surface states increases with rise of the surface concentration in solid solutions with high power factor, and the largest concentration value was observed in the $Bi_{1.98}In_{0.02}Te_{2.85}Se_{0.15}$ composition. The dependences of Fermi energy on the wave vector for different solid solutions are described by a set of Dirac cone sections, which are close within the limits of the fluctuations of the Dirac point energy that explained by weak changes of the Fermi velocity in the compositions at studied atomic substitutions in the bismuth telluride sublattices.
