Propose two-dimensional Sb2Te2X (X = S, Se) with isotropic electron mobility and remarkable visible-light response.

Two-dimensional (2D) crystals are emerging materials for nanoelectronics, and computationally identifying novel 2D materials with distinct electronic and optical properties furnishes a vital first step for future photovoltaic technology. Herein, based on the density functional theory and Keldysh nonequilibrium Green's function formalism, we reported new members of the family of 2D Group V-VI compounds, i.e., Sb2Te2X (X = S, Se) compounds, which exhibited excellent dynamic and thermal stabilities. It was found that 2D Sb2Te2S and Sb2Te2Se possess moderate band gaps of 0.87 and 0.76 eV, respectively, and they are advantageous over other frequently studied 2D materials. Most surprisingly, it was demonstrated that Sb2Te2X has two excellent characteristics, i.e., high isotropic electron mobility surpassing 103 cm2 V-1 s-1 and remarkable optical absorption over the entire visible region with a high photoresponse (∼0.044 A W-1). The exceptional electronic properties in combination with fascinating optical properties illustrate the great potential of Sb2Te2X, for example, in photovoltaic devices, boosting a new area in the research of Group V-VI 2D semiconductors.

[1]  Yu Zhu,et al.  A 4 V Cathode Compatible, Superionic Conductive Solid Polymer Electrolyte for Solid Lithium Metal Batteries with Long Cycle Life , 2018, ACS Applied Energy Materials.

[2]  Jinlan Wang,et al.  Bi2OS2: a direct-gap two-dimensional semiconductor with high carrier mobility and surface electron states , 2018 .

[3]  Claudia Felser,et al.  High-mobility band-like charge transport in a semiconducting two-dimensional metal–organic framework , 2018, Nature Materials.

[4]  Jinxiong Wu,et al.  Electronic structures and unusually robust bandgap in an ultrahigh-mobility layered oxide semiconductor, Bi2O2Se , 2018, Science Advances.

[5]  Ying Dai,et al.  Two-dimensional III2-VI3 materials: Promising photocatalysts for overall water splitting under infrared light spectrum , 2018, Nano Energy.

[6]  Jiaguo Yu,et al.  Metal‐Free 2D/2D Phosphorene/g‐C3N4 Van der Waals Heterojunction for Highly Enhanced Visible‐Light Photocatalytic H2 Production , 2018, Advanced materials.

[7]  Ying Dai,et al.  Tl2S: a metal-shrouded two-dimensional semiconductor. , 2018, Physical chemistry chemical physics : PCCP.

[8]  Ying Dai,et al.  Photoexcitation Dynamics in Janus-MoSSe/WSe2 Heterobilayers: Ab Initio Time-Domain Study. , 2018, The journal of physical chemistry letters.

[9]  A. Molina‐Mendoza,et al.  Atomically thin p-n junctions based on two-dimensional materials. , 2018, Chemical Society reviews.

[10]  Beiyun Liu,et al.  A highly polarization sensitive antimonene photodetector with a broadband photoresponse and strong anisotropy , 2018 .

[11]  Yuanbo Zhang,et al.  Gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe2 , 2018, Nature.

[12]  M. Bonn,et al.  Coupling between intra- and intermolecular motions in liquid water revealed by two-dimensional terahertz-infrared-visible spectroscopy , 2018, Nature Communications.

[13]  M. Cho,et al.  Evolution of the broadband optical transition in large-area MoS e 2 , 2018 .

[14]  L. Dai,et al.  Epitaxial Single‐Layer MoS2 on GaN with Enhanced Valley Helicity , 2018, Advanced materials.

[15]  Qiang Sun,et al.  Bi2O2Se nanosheet: An excellent high-temperature n-type thermoelectric material , 2018 .

[16]  Tianran Li,et al.  Ultrafast and highly sensitive infrared photodetectors based on two-dimensional oxyselenide crystals , 2017, Nature Communications.

[17]  Wei Wei,et al.  Design of new photovoltaic systems based on two-dimensional group-IV monochalcogenides for high performance solar cells , 2017 .

[18]  Hong Guo,et al.  Ohmic contact in monolayer InSe-metal interface , 2017 .

[19]  T. Heine,et al.  Two-Dimensional Haeckelite NbS2 : A Diamagnetic High-Mobility Semiconductor with Nb4+ Ions. , 2017, Angewandte Chemie.

[20]  L. Yin,et al.  Two‐Dimensional Non‐Layered Materials: Synthesis, Properties and Applications , 2017 .

[21]  Chao Xie,et al.  Photodetectors Based on Two‐Dimensional Layered Materials Beyond Graphene , 2017 .

[22]  Jinxiong Wu,et al.  Controlled Synthesis of High-Mobility Atomically Thin Bismuth Oxyselenide Crystals. , 2017, Nano letters.

[23]  Jinxiong Wu,et al.  High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se. , 2017, Nature nanotechnology.

[24]  S. Louie,et al.  Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals , 2017, Nature.

[25]  Ying Dai,et al.  Engineering the electronic and optoelectronic properties of InX (X = S, Se, Te) monolayers via strain. , 2017, Physical chemistry chemical physics : PCCP.

[26]  L. Etgar,et al.  High Efficiency and High Open Circuit Voltage in Quasi 2D Perovskite Based Solar Cells , 2017 .

[27]  D. Graf,et al.  Quantum oscillations in metallic Sb2Te2Se topological insulator , 2017, 1701.01277.

[28]  Jan F. Schmidt,et al.  Correlated fluorescence blinking in two-dimensional semiconductor heterostructures , 2016, Nature.

[29]  L. Tu,et al.  Robustness of a Topologically Protected Surface State in a Sb2Te2Se Single Crystal , 2016, Scientific Reports.

[30]  W. Duan,et al.  Lorentz-violating type-II Dirac fermions in transition metal dichalcogenide PtTe2 , 2016, Nature Communications.

[31]  Qiang Sun,et al.  SiTe monolayers: Si-based analogues of phosphorene , 2016 .

[32]  Qiang Fu,et al.  Catalysis with two-dimensional materials and their heterostructures. , 2016, Nature nanotechnology.

[33]  Zuocheng Zhang,et al.  Direct observation of the layer-dependent electronic structure in phosphorene. , 2016, Nature nanotechnology.

[34]  Kazuhito Tsukagoshi,et al.  Charge transport and mobility engineering in two-dimensional transition metal chalcogenide semiconductors. , 2016, Chemical Society reviews.

[35]  E. Kioupakis,et al.  Anisotropic Spin Transport and Strong Visible-Light Absorbance in Few-Layer SnSe and GeSe. , 2015, Nano letters.

[36]  T. Murakami,et al.  Optical transitions in hybrid perovskite solar cells: Ellipsometry, density functional theory, and quantum efficiency analyses for CH3NH3PbI3 , 2015, 1507.08824.

[37]  I. Tanaka,et al.  First principles phonon calculations in materials science , 2015, 1506.08498.

[38]  K. Loh,et al.  Two-dimensional dichalcogenides for light-harvesting applications , 2015 .

[39]  Dennis Sheberla,et al.  Cu₃(hexaiminotriphenylene)₂: an electrically conductive 2D metal-organic framework for chemiresistive sensing. , 2015, Angewandte Chemie.

[40]  M. Hersam,et al.  Solvent exfoliation of electronic-grade, two-dimensional black phosphorus. , 2015, ACS nano.

[41]  Sean C. Smith,et al.  Structural and Electronic Properties of Layered Arsenic and Antimony Arsenide , 2015 .

[42]  Wei Huang,et al.  Bandgap tuning of multiferroic oxide solar cells , 2014, Nature Photonics.

[43]  Andres Castellanos-Gomez,et al.  Environmental instability of few-layer black phosphorus , 2014, 1410.2608.

[44]  S. Haigh,et al.  Production of few-layer phosphorene by liquid exfoliation of black phosphorus. , 2014, Chemical communications.

[45]  Franccois-Xavier Coudert,et al.  Necessary and Sufficient Elastic Stability Conditions in Various Crystal Systems , 2014, 1410.0065.

[46]  Ryan Soklaski,et al.  Enhanced thermoelectric efficiency via orthogonal electrical and thermal conductances in phosphorene. , 2014, Nano letters.

[47]  Xianfan Xu,et al.  Phosphorene: an unexplored 2D semiconductor with a high hole mobility. , 2014, ACS nano.

[48]  S. De,et al.  Outstanding mechanical properties of monolayer MoS2 and its application in elastic energy storage. , 2013, Physical chemistry chemical physics : PCCP.

[49]  Qi Jie Wang,et al.  Broadband high photoresponse from pure monolayer graphene photodetector , 2013, Nature Communications.

[50]  Qing Hua Wang,et al.  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. , 2012, Nature nanotechnology.

[51]  Hong Guo,et al.  First-principles analysis of photocurrent in graphene P N junctions , 2012, 1202.4980.

[52]  J. Anthony,et al.  Orientation-independent charge transport in single spherulites from solution-processed organic semiconductors. , 2012, Journal of the American Chemical Society.

[53]  M. Vergniory,et al.  The effect of van der Waal's gap expansions on the surface electronic structure of layered topological insulators , 2011, 1107.3208.

[54]  K. Shepard,et al.  Boron nitride substrates for high-quality graphene electronics. , 2010, Nature nanotechnology.

[55]  F. Xia,et al.  Ultrafast graphene photodetector. , 2009, Nature nanotechnology.

[56]  K. Shepard,et al.  Current saturation in zero-bandgap, top-gated graphene field-effect transistors. , 2008, Nature nanotechnology.

[57]  Hong Guo,et al.  Nonlinear spin current and magnetoresistance of molecular tunnel junctions. , 2006, Physical review letters.

[58]  Andre K. Geim,et al.  Electric Field Effect in Atomically Thin Carbon Films , 2004, Science.

[59]  Takashi Taniguchi,et al.  Direct-bandgap properties and evidence for ultraviolet lasing of hexagonal boron nitride single crystal , 2004, Nature materials.

[60]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[61]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[62]  M. Klein,et al.  Nosé-Hoover chains : the canonical ensemble via continuous dynamics , 1992 .

[63]  Axel D. Becke,et al.  A Simple Measure of Electron Localization in Atomic and Molecular-Systems , 1990 .

[64]  E. Borek Nucleic acid modification at Erlangen , 1976, Nature.

[65]  H. Monkhorst,et al.  SPECIAL POINTS FOR BRILLOUIN-ZONE INTEGRATIONS , 1976 .

[66]  J. Bardeen,et al.  Deformation Potentials and Mobilities in Non-Polar Crystals , 1950 .

[67]  Jiang Tang,et al.  Synergistic Effect of Hybrid PbS Quantum Dots/2D‐WSe2 Toward High Performance and Broadband Phototransistors , 2017 .

[68]  Xianfan Xu,et al.  Phosphorene: An Unexplored 2D Semiconductor with a High Hole , 2014 .