Rudenko A N, Brener S, Katsnelson M I
Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen, Netherlands.
Phys Rev Lett. 2016 Jun 17;116(24):246401. doi: 10.1103/PhysRevLett.116.246401. Epub 2016 Jun 14.
We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13} cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (μ_{xx}/μ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300 K), the electron mobility is found to be significantly more anisotropic (μ_{xx}/μ_{yy}∼6.2). Absolute values of μ_{xx} do not exceed 250 (700) cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature.
我们提出了一种适用于单层黑磷（BP）的各向异性二维半导体中单声子和双声子电荷载流子散射的理论。我们表明，与石墨烯不同，在石墨烯中，由弯曲声子散射引起的双声子过程在任何实际相关温度下都占主导，并且与载流子浓度(n)无关，而在BP中，双声子散射不太重要，在(n≳10^{13} cm^{-2})时可视为可忽略不计。然而，在较小的(n)时，声子进入基本非谐区域。与空穴迁移率相比，空穴迁移率在BP的主方向之间没有表现出强烈的各向异性（在(n = 10^{13} cm^{-2})和(T = 300 K)时，(\mu_{xx}/\mu_{yy}∼1.4)），发现电子迁移率具有明显更大的各向异性（(\mu_{xx}/\mu_{yy}∼6.2)）。对于空穴（电子），(\mu_{xx})的绝对值不超过(250（700）cm^{2} V^{-1} s^{-1})，这可以被视为室温下BP迁移率的上限。
