摘要
Two-dimensional(2D)transition metal dichalcogenide(TMD)has emerged as an effective optoelectronics material due to its novel optical properties.Understanding the role of defects in exciton kinetics is crucial for achieving high-efficiency TMD devices.Here,we observe defects induced anomalous power dependence exciton dynamics and spatial distribution in hexagonal heterogeneous WS_(2).With transient absorption microscopy study,we illustrate that these phenomena originate from the competition between radiative and defect-related non-radiative decays.To understand the physics behind this,a decay model is introduced with two defect-related channels,which demonstrates that more excitons decay through non-radiative channels in the dark region than the bright region.Our work reveals the mechanisms of anomalous exciton kinetics by defects and is instrumental for understanding and exploiting excitonic states in emerging 2D semiconductors.
基金
supported by the Ministry of Science and Technology of China(No.2019YFE0120300)
the National Natural Science Foundation of China(No.11904266)
the Fundamental Research Funds for the Central Universities(No.2042021kf0202)
the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF014).
