AI 中文总结
本研究通过第一性原理计算发现，分数量子铁电α-In2Se3因极化源于离散原子位移而避免铁电模散射，室温迁移率超70 cm²/(V s)，掺杂后超300，为高迁移率铁电半导体提供新途径。
AI 中文摘要
铁电半导体有望用于多功能电子器件，但其通常较低的载流子迁移率仍是一个主要限制。通过对单层In$_2$Se$_3$进行基于第一性原理的声子限制输运计算，我们表明这一限制关键取决于铁电性的微观起源。在位移型$β'$-In$_2$Se$_3$中，低频铁电模主导载流子散射，并伴有纵向光学（LO）声子的额外贡献，将室温电子迁移率限制在几个cm$^2$/(V s)。相比之下，在分数量子铁电$α$-In$_2$Se$_3$中，由于极化源于离散的晶格尺度原子位移而非软模凝聚，铁电模散射不存在。因此，输运由LO声子主导，室温迁移率超过70 cm$^2$/(V s)。载流子掺杂进一步屏蔽长程电子-LO声子相互作用，并在实验可达到的密度下将迁移率提升至300 cm$^2$/(V s)以上。这些结果确立了分数量子铁电性可以将稳健极化与强本征载流子散射解耦，为高迁移率铁电半导体提供了一条途径。
英文摘要
Ferroelectric semiconductors are promising for multifunctional electronics, yet their typically low carrier mobilities remain a major limitation. Using first-principles phonon-limited transport calculations for monolayer In$_2$Se$_3$, we show that this limitation depends critically on the microscopic origin of ferroelectricity. In displacive $β'$-In$_2$Se$_3$, low-frequency ferroelectric modes dominate carrier scattering, with additional contributions from longitudinal-optical (LO) phonons, limiting the room-temperature electron mobility to a few cm$^2$/(V s). By contrast, in fractional-quantum ferroelectric $α$-In$_2$Se$_3$, ferroelectric-mode scattering is absent because polarization arises from discrete lattice-scale atomic displacements rather than soft-mode condensation. Transport is therefore dominated by LO phonons, yielding a room-temperature mobility above 70 cm$^2$/(V s). Carrier doping further screens long-range electron-LO-phonon interactions and raises the mobility beyond 300 cm$^2$/(V s) at experimentally accessible densities. These results establish that fractional-quantum ferroelectricity can decouple robust polarization from strong intrinsic carrier scattering, offering a route toward high-mobility ferroelectric semiconductors.
Comments24 pages, 3 main figures and a TOC graphic
