PdSe2: Pentagonal Two-Dimensional Layers with High Air Stability for Electronics

• DOI: 10.1021/jacs.7b04865
• Publication Date: 2017-09-05T22:33:26Z
• Authors: Akinola D. Oyedele; Shize Yang; Liangbo Liang; Alexander A. Pure...; Kai Wang; Jingjie Zhang; Peng Yu; Pushpa R. Pudasaini; Avik W. Ghosh; Zheng Liu; Christopher M. Ro...; Bobby G. Sumpter; Matthew F. Chisholm; Wu Zhou; Philip D. Rack; David B. Geohegan; Kai Xiao
• Keywords: Phosphorene; Ambipolar diffusion

Most studied two-dimensional (2D) materials exhibit isotropic behavior due to high lattice symmetry; however, lower-symmetry 2D such as phosphorene and other elemental very interesting anisotropic properties. In this work, we report the atomic structure, electronic properties, vibrational modes of few-layered PdSe2 exfoliated from bulk crystals, a pentagonal layered noble transition metal dichalcogenide with puckered morphology that is air-stable. Micro-absorption optical spectroscopy first-principles calculations reveal wide band gap variation in material 0 (bulk) 1.3 eV (monolayer). The Raman-active were identified using polarized Raman spectroscopy, strong interlayer interaction was revealed large, thickness-dependent peak shifts, agreeing simulations. Field-effect transistors made few-layer display tunable ambipolar charge carrier conduction electron field-effect mobility ∼158 cm2 V-1 s-1, indicating promise anisotropic, air-stable, for electronics.