Temperature dependence of carrier scattering in polycrystalline bismuth
Temperature dependence of carrier scattering in polycrystalline bismuth
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DOI：
10.1063/1.5110254
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发表时间：
2019-08
影响因子：
3.2
通讯作者：
Taichi Arisaka;M. Otsuka;M. Tokitani;Y. Hasegawa
中科院分区：
文献类型：
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作者：
Taichi Arisaka;M. Otsuka;M. Tokitani;Y. Hasegawa
散射过程对温度的依赖性从50到300 K范围内进行了全面的研究，通过测量五个传输系数（电阻率，磁阻，塞贝克系数，霍尔系数，能斯特系数），使用多晶大块铋。假设载流子散射范围从声学变形势散射到电离杂质散射，计算了五个物理性质（载流子密度、电子和空穴迁移率以及电子和空穴费米能）的值。伴随的载流子的平均自由路径也被评估使用计算的费米能量和有效质量张量。从电子背散射衍射获得的平均自由程和晶粒尺寸（通常为几微米）有助于缩小不同散射过程的分布范围。因此，重新计算了包括散射过程的温度依赖性在内的物理性质，并假设了电子迁移率的实际温度依赖性。定量和定性分析表明，在室温附近，声学形变势散射占主导地位，当平均自由程超过1 μm时，声学形变势散射转变为电离杂质散射。这表明，直接利用与散射过程相关的能斯特系数的测量结果，多晶块体铋的散射过程依赖于晶粒尺寸。计算了铋的带隙能，并估计了散射过程的温度依赖性。结果表明，带隙能量随温度的变化趋势与文献中所描述的相似。最后，本研究提供了多晶铋的物理性质的温度依赖性，在50至300 K范围内的散射过程的温度依赖性进行了全面的研究，通过测量五个输运系数（电阻率，磁阻率，塞贝克系数，霍尔系数，能斯特系数）使用多晶体铋。假设载流子散射范围从声学变形势散射到电离杂质散射，计算了五个物理性质（载流子密度、电子和空穴迁移率以及电子和空穴费米能）的值。伴随的载流子的平均自由路径也被评估使用计算的费米能量和有效质量张量。从电子背散射衍射获得的平均自由程和晶粒尺寸（通常为几微米）有助于缩小不同散射过程的分布范围。因此，重新计算了物理性质，包括散射过程的温度依赖性，并计算了散射过程的实际温度依赖性.
The dependence of the scattering process on temperatures ranging from 50 to 300 K was comprehensively investigated by measuring five transport coefficients (resistivity, magnetoresistivity, Seebeck coefficient, Hall coefficient, and Nernst coefficient) using polycrystalline bulk bismuth. The values of five physical properties (carrier density, electron and hole mobilities, and electron and hole Fermi energies) were calculated assuming that carrier scattering ranged from acoustic deformation potential scattering to ionized impurity scattering. The accompanying mean-free paths of carriers were also evaluated using the calculated Fermi energy and the effective mass tensor. The mean-free path and grain size (typically several micrometers) obtained from electron backscattered diffraction helped narrow the distribution range of the different scattering processes. Thus, the physical properties, including temperature dependence of the scattering processes, were recalculated, and realistic temperature dependence of the electron mobility was assumed. Quantitative and qualitative analyses showed that near room temperature, acoustic deformation potential scattering dominated, which changed to ionized impurity scattering when the estimated mean-free path exceeded 1 μm. This indicated that the scattering process of polycrystalline bulk bismuth depends on the grain size when the measurement results of the Nernst coefficient related to the scattering process are directly used. The bandgap energy of bismuth was also calculated, and the temperature dependence of the scattering process was estimated. The results showed that the temperature dependence tendency of bandgap energy is similar to that described in the literature. Finally, this study provides the temperature dependence of the physical properties of polycrystalline bismuth.The dependence of the scattering process on temperatures ranging from 50 to 300 K was comprehensively investigated by measuring five transport coefficients (resistivity, magnetoresistivity, Seebeck coefficient, Hall coefficient, and Nernst coefficient) using polycrystalline bulk bismuth. The values of five physical properties (carrier density, electron and hole mobilities, and electron and hole Fermi energies) were calculated assuming that carrier scattering ranged from acoustic deformation potential scattering to ionized impurity scattering. The accompanying mean-free paths of carriers were also evaluated using the calculated Fermi energy and the effective mass tensor. The mean-free path and grain size (typically several micrometers) obtained from electron backscattered diffraction helped narrow the distribution range of the different scattering processes. Thus, the physical properties, including temperature dependence of the scattering processes, were recalculated, and realistic temperature dependence o...