We present a theory for single- and two-phonon charge carrier scattering inanisotropic two-dimensional semiconductors applied to single-layer blackphosphorus (BP). We show that in contrast to graphene, where two-phononprocesses due to the scattering by flexural phonons dominate at any practicallyrelevant temperatures and are independent of the carrier concentration $n$,two-phonon scattering in BP is less important and can be considered negligibleat $n\gtrsim10^{13}$ cm$^{-2}$. At smaller $n$, however, phonons enter in theessentially anharmonic regime. Compared to the hole mobility, which does notexhibit strong anisotropy between the principal directions of BP($\mu_{xx}/\mu_{yy}\sim1.4$ at $n=10^{13}$ cm$^{-2}$ and $T=300$ K), theelectron mobility is found to be significantly more anisotropic($\mu_{xx}/\mu_{yy}\sim6.2$). Absolute values of $\mu_{xx}$ do not exceed 250(700) cm$^2$V$^{-1}$s$^{-1}$ for holes (electrons), which can be considered asan upper limit for the mobility in BP at room temperature.
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机译：我们提出了应用于单层黑磷（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，与石墨烯相反，由于弯曲声子的散射，在任何实际相关温度下，两个声子过程均占主导地位，并且与载流子浓度无关，BP中的两个声子散射的重要性较小，在$时可以忽略不计。 n \ gtrsim10 ^ {13} $ cm $ ^ {-2} $。然而，在较小的情况下，声子进入了基本上非谐的状态。与空穴迁移率相比，它在BP（$ \ mu_ {xx} / \ mu_ {yy} \ sim1.4 $在$ n = 10 ^ {13} $ cm $ ^ {- 2} $和$ T = 300 $ K），则发现电子迁移率明显各向异性（$ \ mu_ {xx} / \ mu_ {yy} \ sim6.2 $）。空穴（电子）的绝对值$ \ mu_ {xx} $不超过250（700）cm $ ^ 2 $ V $ ^ {-1} $ s $ ^ {-1} $室温下BP的迁移率极限。
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