Thermodynamically Stable Synthesis of Large-Scale and Highly Crystalline Transition Metal Dichalcogenide Monolayers and their Unipolar n-n Heterojunction Devices.
Jeong, Hu Young
Shin, Hyeon Suk
Morris, Stephen M
Sohn, Jung Inn
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Lee, J., Pak, S., Giraud, P., Lee, Y., Cho, Y., Hong, J., Jang, A., et al. (2017). Thermodynamically Stable Synthesis of Large-Scale and Highly Crystalline Transition Metal Dichalcogenide Monolayers and their Unipolar n-n Heterojunction Devices.. Advanced Materials, 29 (33. 1702206)https://doi.org/10.1002/adma.201702206
Transition metal dichalcogenide (TMDC) monolayers are considered to be potential materials for atomically thin electronics due to their unique electronic and optical properties. However, large-area and uniform growth of TMDC monolayers with large grain sizes is still a considerable challenge. This report presents a simple but effective approach for large-scale and highly crystalline molybdenum disulfide monolayers using a solution-processed precursor deposition. The low supersaturation level, triggered by the evaporation of an extremely thin precursor layer, reduces the nucleation density dramatically under a thermodynamically stable environment, yielding uniform and clean monolayer films and large crystal sizes up to 500 µm. As a result, the photoluminescence exhibits only a small full-width-half-maximum of 48 meV, comparable to that of exfoliated and suspended monolayer crystals. It is confirmed that this growth procedure can be extended to the synthesis of other TMDC monolayers, and robust MoS2 /WS2 heterojunction devices are easily prepared using this synthetic procedure due to the large-sized crystals. The heterojunction device shows a fast response time (≈45 ms) and a significantly high photoresponsivity (≈40 AW-1 ) because of the built-in potential and the majority-carrier transport at the n-n junction. These findings indicate an efficient pathway for the fabrication of high-performance 2D optoelectronic devices.
2D materials, chemical vapor deposition, heterojunctions, photodetectors, transition metal dichalcogenides
Is supplemented by: https://doi.org/10.1002/adma.201702206
European Research Council under the the European Union's Seventh Framework Programme (FP/2007-2013)/Grant Agreement no. 340538 (Project ‘UniQDS’) European Union under H2020 programme Grant Agreement no. 685758 (Project ‘1D-NEON’).
European Commission Horizon 2020 (H2020) ERC (340538)
European Commission Horizon 2020 (H2020) Research Infrastructures (RI) (685758)
External DOI: https://doi.org/10.1002/adma.201702206
This record's URL: https://www.repository.cam.ac.uk/handle/1810/285412