High-throughput Computation of Novel Two-dimensional Materials Jinbo Pan 01-20-2017

“Moore’s Law” --- Evolution of MOSFET Trends in digital electronics. Gordon Moore predicted in 1965: The transistors in integrated circuits doubled every 18 months.

Introdcution to Graphene A monolayer of carbon atoms tightly packed into a two-dimensional honeycomb lattice. High specific surface area High carrier mobility High thermal conductivity High opacity High chemical stability Strongest material up to now ……

Publications related to graphene Year Date from web of science

Other Hot Two-dimensional Materials TMDs M = Ta, Nb, Fe, Co, Mo, … X = S, Se, Te, … X M Silicene, germanene … h-BN Black phosphorus B Black phosphorus, WSe2 （Tungsten diselenide）, MoS2 are semiconductor, FeSe2, CoSe2 are ferromagnet, and NbSe2 （niobium， /naɪ'obɪəm/）is superconductor. These different properties provide opportunities to the diversified demand of the future industry. Semiconductor: Black phosphorus, WSe2, MoS2, … Ferromagnet: FeSe2, CoSe2 ,… Superconductor: NbSe2,…

More 2D Materials Need to Be Explored Nature 522 (2015): 274

Searching Layered Materials from ICSD Database Inorganic Crystal Structure Database (ICSD): Largest inorganic crystal database; contains about 185,000 structures ; about 6,000 added annually.  Strategy on searching 2D materials: Bulk Supercell Bond Connection Monolayer Primitive Cell More than 1000 2D materials were found. Results from Haowei Peng

Statistics of Elements and Atoms in Primitive Cell Elements in a primitive cell: Atoms in a primitive cell: There are plenty of room for 2D materials with multiple-elements and large primitive cell .

Space-groups of 2D Materials in Our Database P2S6Sn2 HfS3 NiO2 GaSe PbS SeTa2 In2Te5 GaPS4 PdSeO3 CoV2O6 10 most common space-groups in our database

Building a Database for 2D Materials Atomic Structure Electronic Structure Phonon Spectrum Thermal conductivity Elastic modulus Metal Semiconductor Transport property Electric polarization Optical property Superconductor el-ph coupling Thermoelectric material Piezoelectric materials

Other Group Focusing on HT 2D-Materials Prof. Nicola Marzari arXiv:1611.05234v1

Example: Mechanism of Water-splitting H+/H2 O2/H2O H2 H+ e- Water reduction Conduction band e- e- e- e- 2H+ + 2e-  H2 H2O + 2h+  𝟏 𝟐 O2 + 2H+ hν H2O O2 h+ Water oxidation h+ h+ h+ h+ Valence band Redox reaction: H2O + hν  𝟏 𝟐 O2 + H2

How to Find a Good Candidate for Water-splitting? Thermodynamically stable Suitable band gap Suitable band edges Stable in water

Band Levels of Various Semiconductor Materials ZrO2（zirconium [zɚ'konɪəm]）, TiO2 （titanium）possess suitable band structures. Although CdS (Cadmium ['kædmɪəm]) seems to have a suitable band position and band gap Both stable and more efficient materials need to be further explored. Chem. Soc. Rev. 38, 253 (2009)

Band Gaps in Our Database (Nonmetallic)

Band Edges for Binary 2D Compounds in Our Database H+/H2 H+/H2

Optimal Band Edges for Water Splitting in Our Database B3Eu2Li3O9 PdSeO3 Br7STa3 PdSe2 BrCuTe Mn2P2Se6 Br2NbSe2 CoI2 P2S6V2 CuITe2 Br2CdSb2Se3 FePSe3 P2S6Sn2 ClCuTe2 Cl7Nb3Te PPdSe ClCuHgS Bi2PbTe4 NiPSe3 PdS2 BrCuTe2 Cl4Hg4I2S I3S2SbSn2 P2Si BiCuP2Se6 Ba2F2Sb2Se4 Co2P2S6 Cl2NbSe2 Bi2GeTe4 H+/H2 O2/H2O Direct Gap Indirect Gap shows the anion of these materials, including O, S, Se, tellurium,P,chlorine,bromine,iodine. -0.6 eV ≤ CBM ≤ 0 eV; 1.2 eV ≤ VBM ≤ 1.8 eV

Band and PDOS of Monolayer PdSeO3 Г X S Y Г Pd has the largest contribution to the DOS near Ef level.

Outlook High-throughput computations of 2D band structures Electrochemical and thermodynamic stability analysis Novel photoelectrochemical cell with 2D heterostructures Other application of these 2D-materials

Acknowledgements Advisor: Collaborators: Funding: Computing resource: Qimin Yan Haowei Peng Jie Yu John P. Perdew Funding: Computing resource:

Thank you for your attention

PDOS of PdSeO3 on Pd