Open AccessOptical characteristics of bilayer decoupling MoS2 grown by the CVD method
Author(s) -
Xiaowen Hu,
Mingming Yang,
Yufan Zhang,
Heng Wu,
Zhengkang Yu,
Qi Guo,
Ying Wang,
Rongjuan Cong,
Baolai Liang,
Xiaoli Li
Publication year - 2022
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.469797
Subject(s) - exciton , photoluminescence , bilayer , materials science , raman spectroscopy , decoupling (probability) , band gap , optoelectronics , excitation , spontaneous emission , molecular physics , condensed matter physics , optics , physics , chemistry , laser , biochemistry , engineering , quantum mechanics , control engineering , membrane
Study of exciton recombination process is of great significance for the optoelectronic device applications of two-dimensional transition metal chalcogenides (TMDCs). This research investigated the decoupling MoS 2 structures by photoluminescence (PL) measurements. First, PL intensity of the bilayer MoS 2 (BLM) is about twice of that of the single layer MoS 2 (SLM) at low temperature, indicating no transition from direct bandgap to indirect bandgap for BLM due to the decrease of interlayer coupling which can be shown by Raman spectra. Then, the localized exciton emission appears for SLM at 7 K but none for BLM, showing different exciton localization characteristics. The PL evolution with respect to the excitation intensity and the temperature further reveal the filling, interaction, and the redistribution among free exciton states and localized exciton states. These results provide very useful information for understanding the localized states and carrier dynamics in BLM and SLM.