Paper 2D+AS+SS-ThA1
Electron Irradiation-induced Defects and Phase Transformations in Two-dimensional Inorganic Materials

Thursday, November 2, 2017, 2:20 pm, Room 15

Following isolation of a single sheet of graphene, many other 2D systems such as hexagonal BN, transition metal dichalcogenides (TMDs) and silica bilayers were manufactured. All these systems contain defects and impurities, which may govern the electronic and optical properties of these materials, calling upon the studies on defect properties. In my talk, I will present the results [1-6] 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 dwell on the signatures of defects in Raman spectra and discuss defect- and impurity-mediated engineering of the electronic structure of inorganic 2D materials. I will also present the results [7] of our theoretical studies of electron-beam induced phase transformations in 2D TMDs when electric charge, mechanical strain and vacancies are present. Based on the results of our calculations, we propose an explanation for this phenomenon which is likely promoted by charge redistribution in the TMD monolayer combined with vacancy formation due to electron beam and associated mechanical strain in the sample.

References

1. E. Sutter et al., Nano Letters 16, 21 (2016).

2. T. Björkman et al., ACS Nano 10, 10929 (2016).

3. M. Ghorbani-Asl et al., 2D Materials 4 (2017) 025078.

4. H.-P. Komsa and A.V. Krasheninnikov, Adv. El. Mat. (2017) 1600468.

5. L. Nguyen, et al., ACS Nano 11 (2017) 2894.

6. C. Herbig, et al. Nano Letters (2017) DOI: 10.1021/acs.nanolett.7b00550.

7. S. Kretschmer et al., submitted.