Open AccessControl of Radiative Exciton Recombination by Charge Transfer Induced Surface Dipoles in MoS2 and WS2 Monolayers
Author(s) -
Peng Hu,
Jun Ye,
Xuexia He,
KeZhao Du,
Keke K. Zhang,
Xingzhi Wang,
Qihua Xiong,
Zheng Liu,
Hui Jiang,
Christian Kloc
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep24105
Subject(s) - monolayer , exciton , photoluminescence , dipole , acceptor , electron , radiative transfer , materials science , spontaneous emission , recombination , phonon , molecular physics , atomic physics , condensed matter physics , chemistry , optoelectronics , physics , laser , nanotechnology , optics , biochemistry , organic chemistry , quantum mechanics , gene
Due to the two dimensional confinement of electrons in a monolayer of 2D materials, the properties of monolayer can be controlled by electrical field formed on the monolayer surface. F 4 TCNQ was evaporated on MoS 2 and WS 2 monolayer forming dipoles between strong acceptor, F 4 TCNQ, and monolayers of MoS 2 or WS 2 . The strong acceptor attracts electrons (charge transfer) and decreases the number of the ionized excitons. Free excitons undergo radiative recombination in both MoS 2 and WS 2 . Moreover, the photoluminescence enhancement is stronger in WS 2 where the exciton-phonon coupling is weaker. The theoretical model indicates that the surface dipole controls the radiative exciton recombination and enhances photoluminescence radiation. Deposition of F 4 TCNQ on the 2D monolayers enables a convenient control of the radiative exciton recombination and leads to the applications of these materials in lasers or LEDs.