PdSe2: Pentagonal Two-Dimensional Layers with High Air Stability for Electronics
PdSe2: Pentagonal Two-Dimensional Layers with High Air Stability for Electronics
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DOI：
10.1021/jacs.7b04865
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发表时间：
2017-10-11
影响因子：
15
通讯作者：
Xiao, Kai
中科院分区：
文献类型：
--
作者：
Oyedele, Akinola D.;Yang, Shize;Xiao, Kai
大多数研究的二维（2D）材料由于高晶格对称性而表现出各向同性行为;然而，较低对称性的2D材料，如磷烯和其他元素2D材料表现出非常有趣的各向异性特性。在这项工作中，我们报告的原子结构，电子性质，和振动模式的几个层状PdSe 2剥离大块晶体，一个五边形的2D层状贵过渡金属dichalcogenide与褶皱的形态，是空气稳定的。微吸收光谱和第一性原理计算揭示了宽的带隙变化，这种材料从0（散装）到1.3 eV（单层）。PdSe 2的拉曼活性振动模式被确定使用偏振拉曼光谱，并揭示了一个强大的层间相互作用，从大的，厚度依赖的拉曼峰位移，符合第一性原理拉曼模拟。由少层PdSe 2制成的场效应晶体管显示出可调的双极电荷载流子传导，具有类似于158 cm（2）V-1 s（-1）的高电子场效应迁移率，表明这种各向异性、空气稳定、五边形2D材料用于2D电子器件的前景。
Most studied two-dimensional (2D) materials exhibit isotropic behavior due to high lattice symmetry; however, lower-symmetry 2D materials such as phosphorene and other elemental 2D materials exhibit very interesting anisotropic properties. In this work, we report the atomic structure, electronic properties, and vibrational modes of few layered PdSe2 exfoliated from bulk crystals, a pentagonal 2D layered noble transition metal dichalcogenide with a puckered morphology that is air stable. Micro-absorption optical spectroscopy and first-principles calculations reveal a wide band gap variation in, this material from 0 (bulk) to 1.3 eV (monolayer). The Raman-active vibrational modes of PdSe2 were identified using polarized Raman spectroscopy, and a strong interlayer interaction was revealed from large, thickness-dependent Raman peak shifts, agreeing with first-principles Raman simulations. Field-effect transistors made from the few-layer PdSe2 display tunable ambipolar charge carrier conduction with a high electron field-effect mobility of similar to 158 cm(2) V-1 s(-1),indicating the promise of this anisotropic, air-stable, pentagonal 2D material for 2D electronics.