Defects in two-dimensional materials: their production under irradiation, evolution and properties from first-principles calculations

Following isolation of a single sheet of graphene, many other 2D systems such as hexagonal BN sheets and transition metal dichalcogenides (TMD) were manufactured. Among them, TMD sheets have received particular attention, as these materials exhibit intriguing. Moreover, the properties can further be tuned by introduction of defects and impurities. In my talk, I will present the results (see refs.) of our first-principles theoretical studies of defects (native and irradiation-induced) in inorganic 2D systems obtained in collaboration with several experimental groups. I will further discuss defect- and impurity-mediated engineering of the electronic structure of 2D materials.

• Three-fold rotational defects in two-dimensional transition metal dichalcogenides
  Y.-C. Lin, T.Björkman, H.-P. Komsa, P.-Y. Teng, C.-H. Yeh, F.-S. Huang, K.-H. Lin, J. Jadczak, Y.-S. Huang, P.-W. Chiu, A.V. Krasheninnikov & K. Suenaga, Nature Comm. 6 (2015) 6736.
• Atomic scale microstructure and properties of Se-deficient two-dimensional MoSe₂
  O.Lehtinen, H.-P.Komsa, A.Pulkin, M.B. Whitwick, M.W. Chen, T.Lehnert, M.J. Mohn, O.V. Yazyev, A. Kis, U.Kaiser, and A.V. Krasheninnikov, ACS Nano 9 (2015) 3274.
• Single-layer ReS₂: Two-dimensional semiconductor with tunable in-plane anisotropy
  Y.C.Lin, H.P. Komsa, C.H. Yeh, T.Björkman, Z.-Y. Liang, C.H. Ho, Y.-S. Huang, P.-W.Chiu, A.V. Krasheninnikov, and K. Suenaga, ACS Nano (2015) .
• Native defects in bulk and monolayer MoS₂ from first principles
  H.-P. Komsa and A. V. Krasheninnikov, Phys. Rev. B 91 (2015) 125304.
• Properties of individual dopant atoms in single-layer MoS2: atomic structure, migration, and enhanced reactivity.
  Y.C. Lin, D.O Dumcenco, H.P. Komsa, Y. Niimi, A.V. Krasheninnikov, Y.S. Huang, K. Suenaga., Adv. Mater. 26 (2014) 2857.
• Charged point defects in the flatland: accurate formation energy calculations in two-dimensional materials,
  H.-P. Komsa, N. Berseneva, A.V. Krasheninnikov, and R.M. Nieminen, Phys. Rev. X 4 (2014) 031044.

Complete list of publications.

Helmholtz Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Germany and Department of Applied Physics, Aalto University, Finland