All-optical dynamic tuning of local excitonic emission of monolayer MoS 2 by integration with Ge 2 Sb 2 Te 5

Nanophotonics

article

Hao Ouyang¹  Tian Jiang¹  Haitao Chen¹  Yuxiang Tang¹  Jun Zhang¹  Chenxi Zhang¹  Bin Zhang²  Xiang’ai Cheng¹ 

[1] College of Advanced Interdisciplinary Studies, National University of Defence Technology;Key Laboratory of Optoelectronic Materials and Technologies, School of Electrical and Information Technology, Sun Yat-sen University

关键词: 2D materials;    exciton;    all-optical;    integration;    photoluminescence;   

DOI  :  10.1515/nanoph-2019-0366

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Strong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS 2 hybridized with phase-change material Ge 2 Sb 2 Te 5 (GST) thin film. By applying pulsed laser with different power on the MoS 2 /GST heterostructure, the peak energies of the excitonic emission of MoS 2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS 2 . The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks.

【 授权许可】

CC BY