Striated 2D Lattice with Sub‐nm 1D Etch Channels by Controlled Thermally Induced Phase Transformations of PdSe2

2D crystals are typically uniform and periodic in‐plane with stacked sheet‐like structure in the out‐of‐plane direction. Breaking the in‐plane 2D symmetry by creating unique lattice structures offers anisotropic electronic and optical responses that have potential in nanoelectronics. However, creating nanoscale‐modulated anisotropic 2D lattices is challenging and is mostly done using top‐down lithographic methods with ≈10 nm resolution. A phase transformation mechanism for creating 2D striated lattice systems is revealed, where controlled thermal annealing induces Se loss in few‐layered PdSe2 and leads to 1D sub‐nm etched channels in Pd2Se3 bilayers. These striated 2D crystals cannot be described by a typical unit cells of 1–2 Å for crystals, but rather long range nanoscale periodicity in each three directions. The 1D channels give rise to localized conduction states, which have no bulk layered counterpart or monolayer form. These results show how the known family of 2D crystals can be extended beyond those that exist as bulk layered van der Waals crystals by exploiting phase transformations by elemental depletion in binary systems.

[1]  F. Grønvold,et al.  The crystal structure of PdSe2 and PdS2 , 1957 .

[2]  G. Meyrick,et al.  Phase Transformations in Metals and Alloys , 1973 .

[3]  R. A. Farrar,et al.  Influence of oxygen-rich inclusions on the γ→α phase transformation in high-strength low-alloy (HSLA) steel weld metals , 1981 .

[4]  K. Reeson,et al.  Mechanism of buried β-SiC formation by implanted carbon in silicon , 1990 .

[5]  P. Stolk,et al.  Pulsed‐laser crystallization of amorphous silicon layers buried in a crystalline matrix , 1990 .

[6]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[7]  G. Kresse,et al.  Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set , 1996 .

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

[9]  Steven G. Louie,et al.  MICROSCOPIC DETERMINATION OF THE INTERLAYER BINDING ENERGY IN GRAPHITE , 1998 .

[10]  G. Kresse,et al.  From ultrasoft pseudopotentials to the projector augmented-wave method , 1999 .

[11]  S. Zwaag,et al.  Grain Nucleation and Growth During Phase Transformations , 2002, Science.

[12]  M. McMahon,et al.  High-pressure structures and phase transformations in elemental metals. , 2006, Chemical Society reviews.

[13]  L. Largeau,et al.  Wurtzite to zinc blende phase transition in GaAs nanowires induced by epitaxial burying. , 2008, Nano letters.

[14]  Li‐Min Liu,et al.  Dimension-dependent phase transition and magnetic properties of VS2 , 2013 .

[15]  Simon Kurasch,et al.  From point to extended defects in two-dimensional MoS2: Evolution of atomic structure under electron irradiation , 2013 .

[16]  E. Reed,et al.  Structural phase transitions in two-dimensional Mo- and W-dichalcogenide monolayers , 2014, Nature Communications.

[17]  A. Mohite,et al.  Phase engineering of transition metal dichalcogenides. , 2015, Chemical Society reviews.

[18]  David J. Singh,et al.  Electronic, transport, and optical properties of bulk and mono-layer PdSe2 , 2015 .

[19]  R. Ruoff,et al.  Atomic-scale dynamics of triangular hole growth in monolayer hexagonal boron nitride under electron irradiation. , 2015, Nanoscale.

[20]  Adrienn Ruzsinszky,et al.  Strongly Constrained and Appropriately Normed Semilocal Density Functional. , 2015, Physical review letters.

[21]  Zhongfang Chen,et al.  Not your familiar two dimensional transition metal disulfide: structural and electronic properties of the PdS2 monolayer , 2015 .

[22]  Jianwei Sun,et al.  Accurate first-principles structures and energies of diversely bonded systems from an efficient density functional. , 2016, Nature chemistry.

[23]  Moon J. Kim,et al.  Line-defect mediated formation of hole and Mo clusters in monolayer molybdenum disulfide , 2016 .

[24]  J. Warner,et al.  Detailed Atomic Reconstruction of Extended Line Defects in Monolayer MoS2. , 2016, ACS nano.

[25]  Yao Li,et al.  Structural semiconductor-to-semimetal phase transition in two-dimensional materials induced by electrostatic gating , 2016, Nature Communications.

[26]  H. Sawada,et al.  Atomic structure and formation mechanism of sub-nanometer pores in 2D monolayer MoS2. , 2017, Nanoscale.

[27]  Peng Yu,et al.  PdSe2: Pentagonal Two-Dimensional Layers with High Air Stability for Electronics. , 2017, Journal of the American Chemical Society.

[28]  E. Reed,et al.  Structural phase transition in monolayer MoTe2 driven by electrostatic doping , 2017, Nature.

[29]  S. Pantelides,et al.  A novel Pd2Se3 two-dimensional phase driven by interlayer fusion in layered PdSe2 , 2017, Microscopy and Microanalysis.

[30]  Dumitru Dumcenco,et al.  Geometrical Effect in 2D Nanopores. , 2017, Nano letters.

[31]  C. Wolverton,et al.  Pd2Se3 Monolayer: A Promising Two-Dimensional Thermoelectric Material with Ultralow Lattice Thermal Conductivity and High Power Factor , 2018, Chemistry of Materials.

[32]  H. Sawada,et al.  Ultralong 1D Vacancy Channels for Rapid Atomic Migration during 2D Void Formation in Monolayer MoS2. , 2018, ACS nano.

[33]  S. Pantelides,et al.  Two-dimensional PdSe2-Pd2Se3 junctions can serve as nanowires , 2018, 2D Materials.

[34]  G. Ryu,et al.  Atomic Structure and Dynamics of Self-Limiting Sub-Nanometer Pores in Monolayer WS2. , 2018, ACS nano.

[35]  S. Pantelides,et al.  Defect-Mediated Phase Transformation in Anisotropic Two-Dimensional PdSe2 Crystals for Seamless Electrical Contacts. , 2019, Journal of the American Chemical Society.

[36]  G. Ryu,et al.  Atomic Structure and Dynamics of Defects and Grain Boundaries in 2D Pd2Se3 Monolayers. , 2019, ACS nano.

[37]  Yaliang Li,et al.  SCI , 2021, Proceedings of the 30th ACM International Conference on Information & Knowledge Management.