title: Nonblinking, intense two-dimensional light emitter: monolayer WS2 triangles.
abstract: Monolayer WS2 (1L-WS2), with a direct band gap, provides an ideal platform to investigate unique properties of two-dimensional semiconductors. In this work, light emission of a 1L-WS2 triangle has been studied by using steady-state, time-resolved, and temperature-dependent photoluminescence (PL) spectroscopy. Two groups of 1L-WS2 triangles have been grown by chemical vapor deposition, which exhibit nonuniform and uniform PL, respectively. Observed nonuniform PL features, i.e., quenching and blue-shift in certain areas, are caused by structural imperfection and n-doping induced by charged defects. Uniform PL is found to be intrinsic, intense, and nonblinking, which are attributed to high crystalline quality. The binding energy of the A-exciton is extracted experimentally, which gives direct evidence for the large excitonic effect in 1L-WS2. These superior photon emission features make 1L-WS2 an appealing material for optoelectronic applications such as novel light-emitting and biosensing devices.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371.
authors.forename: Namphung
authors.initials: N
authors.lastname: Peimyoo
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Shang
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Cong
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Shen
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Wu
authors.forename: Edwin K L
authors.initials: EK
authors.lastname: Yeow
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003460:Crystallization; D007700:Kinetics; D007834:Lasers; D008027:Light; D049449:Luminescence; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D055095:Optics and Photonics; D010777:Photochemistry; D012666:Semiconductors; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013696:Temperature