School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, China.
Department of Chemistry and Department of Mechanical & Materials Engineering, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
Nano Lett. 2016 May 11;16(5):3236-41. doi: 10.1021/acs.nanolett.6b00726. Epub 2016 Apr 26.
Phosphorene and phosphorene analogues such as SnS and SnSe monolayers are promising nanoelectronic materials with desired bandgap, high carrier mobility, and anisotropic structures. Here, we show first-principles calculation evidence that these monolayers are potentially the long-sought two-dimensional (2D) materials that can combine electronic transistor characteristic with nonvolatile memory readable/writeable capability at ambient condition. Specifically, phosphorene is predicted to be a 2D intrinsic ferroelastic material with ultrahigh reversible strain, whereas SnS, SnSe, GeS, and GeSe monolayers are multiferroic with coupled ferroelectricity and ferroelasticity. Moreover, their low-switching barriers render room-temperature nonvolatile memory accessible, and their notable structural anisotropy enables ferroelastic or ferroelectric switching readily readable via electrical, thermal, optical, mechanical, or even spintronic detection upon the swapping of the zigzag and armchair direction. In addition, it is predicted that the GeS and GeSe monolayers as well as bulk SnS and SnSe can maintain their ferroelasticity and ferroelectricity (anti-ferroelectricity) beyond the room temperature, suggesting high potential for practical device application.
磷烯和类似物如 SnS 和 SnSe 单层是很有前途的纳米电子材料，具有理想的带隙、高载流子迁移率和各向异性结构。在这里，我们通过第一性原理计算证明，这些单层可能是长期以来人们所追求的二维（2D）材料，它可以将电子晶体管特性与在环境条件下可读/可写的非易失性存储器结合起来。具体来说，磷烯被预测为一种具有超高可恢复应变的二维本征铁弹性材料，而 SnS、SnSe、GeS 和 GeSe 单层则是具有铁电性和铁弹性耦合的多铁性材料。此外，它们的低开关势垒使得室温下的非易失性存储器变得可用，并且它们显著的结构各向异性使得铁弹性或铁电切换可以通过电、热、光、机械甚至自旋电子学检测轻易地读取，只需在锯齿形和扶手椅方向之间切换。此外，预计 GeS 和 GeSe 单层以及块状 SnS 和 SnSe 可以在室温以上保持其铁弹性和铁电性（反铁电性），这表明它们在实际器件应用中有很高的潜力。
