Tailoring of Bound Exciton Photoluminescence Emission in WS2 Monolayers. Issue 2 (14th August 2019)

• Record Type: Journal Article
• Authors: Kaupmees, Reelika; Grossberg, Maarja; Ney, Marcel; Asaithambi, Aswin; Lorke, Axel; Krustok, Jüri
• Other Names: Caporali Maria guestEditor.; Grüneis Alexander guestEditor.; Heun Stefan guestEditor.; Szkopek Thomas guestEditor.
• Is Part Of: Physica status solidi. Volume 14:Issue 2(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-14
• Subjects: chemical vapor deposition -- defects -- monolayers -- photoluminescence -- WS2; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201900355
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Temperature‐ and laser power‐dependent photoluminescence (PL) properties of the asymmetric defect‐bound exciton band X D in defective WS2 monolayers, grown by chemical vapor deposition, are studied. Based on PL mapping, a monolayer region with an intensive X D band emission at about 1.9 eV is chosen for further studies. The X D band is thermally quenched above 180 K, and the thermal activation energy is found to be E a = 33 ± 4 meV. At T = 15 K, the X D band intensity reveals a sublinear dependence with increasing excitation power and the peak position shows a blueshift of about 15 meV per decade of laser power. It is shown that the X D band is related to the deep defect states within the band gap of WS2 . Abstract : Temperature‐ and laser power‐dependent photoluminescence properties of the asymmetric defect‐bound exciton band X D in defective WS2 monolayers, grown by chemical vapor deposition, are studied. Herein, it is proposed that the X D band is related to the deep defects (probably sulfur vacancies), whereas the structural defects and adsorbed atoms can also be the cause of these deep defects.