论文标题
BX（x = p，as，sb）单层中具有异常高的声子受限载体迁移率
Exceptionally high phonon-limited carrier mobility in BX (X = P, As, Sb) monolayers
论文作者
论文摘要
仍然缺乏与三维（3D）SI或GAA相当的较高迁移率的理想二维（2D）半导体，仍缺乏妨碍高性能2D设备的发展。在这项工作中，使用第一原理计算并考虑所有电子音波耦合，我们表明单层BX（X = P，as，sb）带有蜂蜜晶格具有固有的声子持续的载载式迁移率，达到创纪录的载体，达到了创纪录的创纪录的高度值，达到了1200-14000 $ CM^2v^2v^2v^{-1} s^room at Perivation 1200-14000 $ cm^2v^{ - 1} s^ - 1}尽管是极性的，并且带有多个山谷的带边缘位于K点，但这三个系统异常具有较小的载体散射速率。详细的分析表明，在两个等效k点之间的Interavalley散射和间隔散射都很弱，可以从电子带和声子频谱之间的大不匹配以及抑制电子偶联强度来理解。 Furthermore, we reveal the general trend of mobility increase from BP to BAs and to BSb and conclude that: smaller effective masses, larger sound velocities, higher optical phonon energies, heavy atomic masses, and out-of-plane orbitals tend to result in small match between the electron and phonon bands, small electron-phonon coupling strengths, and thus high mobility.我们的工作表明，2D半导体可以实现与3D GAA的可比载体迁移率，从而向2D高性能电子设备打开门。
Ideal two-dimensional (2D) semiconductors with high mobility comparable to three-dimensional (3D) Si or GaAs are still lacking, hindering the development of high-performance 2D devices. Here in this work, using first-principles calculations and considering all the electron-phonon couplings, we show that monolayer BX (X = P, As, Sb) with honeycomb lattices have intrinsic phonon-limited carrier mobility reaching record-high values of 1200-14000 $cm^2V^{-1}s^{-1}$ at room temperature. Despite being polar and the band edges located at the K point with multiple valleys, these three systems unusually have small carrier scattering rates. Detailed analysis shows that, both the intravalley scattering and the intervalley scattering between two equivalent K points are weak, which can be understood from the large mismatch between the electron bands and phonon spectrum and suppressed electron-phonon coupling strength. Furthermore, we reveal the general trend of mobility increase from BP to BAs and to BSb and conclude that: smaller effective masses, larger sound velocities, higher optical phonon energies, heavy atomic masses, and out-of-plane orbitals tend to result in small match between the electron and phonon bands, small electron-phonon coupling strengths, and thus high mobility. Our work demonstrates that 2D semiconductors can achieve comparable carrier mobility to 3D GaAs, thus opening doors to 2D high-performance electronic devices.
