Signatures of defect-localized charged excitons in the photoluminescence of monolayer molybdenum disulfide

Neumann, Andre; Lindlau, Jessica; Nutz, Manuel; Mohite, Aditya D.; Yamaguchi, Hisato and Hoegele, Alexander (2018): Signatures of defect-localized charged excitons in the photoluminescence of monolayer molybdenum disulfide. In: Physical Review Materials, Vol. 2, No. 12, 124003

Abstract

We study spatial photoluminescence characteristics of neutral and charged excitons across extended mono-layer MoS2 synthesized by chemical vapor deposition. Using two-dimensional hyperspectral photoluminescence mapping at cryogenic temperatures we identify regions with increased emission from charged excitons associated with both spin-orbit split valence subbands. Such regions are attributed to unintentional doping at defect sites with excess charge that bind neutral excitons to form defect-pinned trions. Our findings imply comparable timescales for the formation, relaxation, and radiative decay of B trions, and add defect-localized A and B trions to the realm of photoexcited quasiparticles in layered semiconductors.

• Item Type: Journal article
• Research Centers: Center for NanoScience (CENS)
• Subjects: 500 Science > 500 Science
• ISSN: 2475-9953
• Language: English