Ultrahigh-resolution nonlinear optical imaging of the armchair orientation in 2D transition metal dichalcogenides
| Autor: | George Kioseoglou, Sotiris Psilodimitrakopoulos, Ioannis Paradisanos, Andreas Lemonis, Emmanuel Stratakis, Leonidas Mouchliadis |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Fabrication
Materials science 02 engineering and technology Crystal structure 010402 general chemistry 01 natural sciences Article law.invention atomically thin transition metal dichalcogenides Optical microscope Transition metal law Monolayer business.industry Orientation (computer vision) Resolution (electron density) 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Nonlinear system graphene-related materials Optoelectronics polarization-resolved second-harmonic generation crystal quality marker armchair orientation mapping 0210 nano-technology business |
| Zdroj: | Light, Science & Applications Light: Science & Applications |
| ISSN: | 2047-7538 2095-5545 |
| Popis: | We used nonlinear laser scanning optical microscopy to study atomically thin transition metal dichalcogenides (TMDs) and revealed, with unprecedented resolution, the orientational distribution of armchair directions and their degree of organization in the two-dimensional (2D) crystal lattice. In particular, we carried out polarization-resolved second-harmonic generation (PSHG) imaging for monolayer WS2 and obtained, with high-precision, the orientation of the main crystallographic axis (armchair orientation) for each individual 120 × 120 nm2 pixel of the 2D crystal area. Such nanoscale resolution was realized by fitting the experimental PSHG images, obtained with sub-micron precision, to a new generalized theoretical model that accounts for the nonlinear optical properties of TMDs. This enabled us to distinguish between different crystallographic domains, locate boundaries and reveal fine structure. As a consequence, we can calculate the mean orientational average of armchair angle distributions in specific regions of interest and define the corresponding standard deviation as a figure-of-merit for the 2D crystal quality. |
| Databáze: | OpenAIRE |
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