Room Temperature Micro-Photoluminescence Studies of Colloidal WS2 Nanosheets

André Philipp Frauendorf; André Niebur; Lena Harms; Shivangi Shree; Bernhard Urbaszek; Michael Oestreich; Jens Hübner; Jannika Lauth

doi:10.1021/acs.jpcc.1c06240

arXiv · 2105.09593

Room Temperature Micro-Photoluminescence Studies of Colloidal WS2 Nanosheets

André Philipp Frauendorf·André Niebur·Lena Harms·Shivangi Shree·Bernhard Urbaszek·Michael Oestreich·Jens Hübner·Jannika Lauth

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Abstract

Wet-chemical syntheses for quasi two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as promising methods for straightforward solution-processing of these materials. However, photoluminescence properties of colloidal TMDs are virtually unexplored due to the typically non-emitting synthesis products. In this work, we demonstrate room temperature micro-photoluminescence of delicate ultrathin colloidal WS2 nanosheets synthesized from WCl6 and elemental sulfur in oleic acid and oleylamine at 320 {\deg}C for the first time. Both, mono- and multilayer photoluminescence are observed, revealing comparable characteristics to exfoliated TMD monolayers and underpinning the high quality of colloidal WS2 nanosheets. In addition, a promising long-term air-stability of colloidal WS2 nanosheets is found and the control of photodegradation of the structures under laser excitation is identified as a challenge for further advancing nanosheet monolayers. Our results render colloidal TMDs as easily synthesized and highly promising 2D semiconductors with optical properties fully competitive with conventionally fabricated ultrathin TMDs.

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André Philipp Frauendorf, André Niebur, Lena Harms, Shivangi Shree, Bernhard Urbaszek, Michael Oestreich, Jens Hübner, Jannika Lauth. 2021-05-20. Room Temperature Micro-Photoluminescence Studies of Colloidal WS2 Nanosheets. https://doi.org/10.1021/acs.jpcc.1c06240

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