Dresden 2017 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 44: Postersession II
DS 44.12: Poster
Donnerstag, 23. März 2017, 17:00–19:00, P1C
Defect induced photoluminescence of tungsten di-sulfide monolayers — •Aswin Asaithambi1, Roland Kozubek1, Guenther Prinz1, Francesco Reale2, Cecilia Mattevi2, Marika Schleberger1, and Axel Lorke1 — 1Faculty of Physics and CENIDE, University of Duisburg-Essen, Duisburg, Germany — 2Department of Materials, Imperial College London, London, UK
The intriguing electronic properties of graphene have renewed the interest in other 2D materials such as transition metal di-chalcogenides (TMDCs) monolayers. TMDCs, similar to graphite, have a layered structure with an indirect bandgap which becomes direct when only a monolayer is present. This leads to strongly enhanced photoluminescence (PL). However, unavoidable defects affect the opto-electronic properties of TMDC monolayers drastically, which makes it necessary to study and characterize their optical related properties.
In this contribution, we present highly sensitive, non-destructive, temperature and power dependent PL measurements to study the defects present in tungsten di-sulfide (WS2) monolayers. For this purpose, pristine samples of WS2 were irradiated with Xe30+ ions to additionally create defects in the monolayers. Low temperature spectra of pristine samples show two different peaks associated with free and defect-bound excitons recombinations. For higher temperature or power, only the free exciton recombinations dominate the spectrum. For the different defect densities created in the monolayers, we observed changes in the PL spectrum with regard to intensity and FWHM, which will be discussed and compared to data published in literature.