Stacking angle dependent multiple excitonic resonances in bilayer tungsten diselenide

Nanophotonics

article

Ankit Arora¹  Pramoda K. Nayak²  Tejendra Dixit²  Kolla Lakshmi Ganapathi²  Ananth Krishnan¹  Mamidanna Sri Ramachandra Rao² 

[1] Centre for NEMS and Nano Photonics, Department of Electrical Engineering, Indian Institute of Technology Madras;Department of Physics and Materials Science Research Centre, Indian Institute of Technology Madras;Nano Functional Materials Technology Centre, Indian Institute of Technology Madras;Department of Electronics and Communication Engineering, Indian Institute of Information Technology D&M

关键词: 2D transition metal dichalcogenides;    bilayer WSe2;    exitonic device;    many-body dynamics;    multiple exitonic resonances;    stacking angle;   

DOI  :  10.1515/nanoph-2020-0034

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

We report on multiple excitonic resonances in bilayer tungsten diselenide (BL-WSe 2 ) stacked at different angles and demonstrate the use of the stacking angle to control the occurrence of these excitations. BL-WSe 2 with different stacking angles were fabricated by stacking chemical vapour deposited monolayers and analysed using photoluminescence measurements in the temperature range 300–100 K. At reduced temperatures, several excitonic features were observed and the occurrences of these exitonic resonances were found to be stacking angle dependent. Our results indicate that by controlling the stacking angle, it is possible to excite or quench higher order excitations to tune the excitonic flux in optoelectronic devices. We attribute the presence/absence of multiple higher order excitons to the strength of interlayer coupling and doping effect from SiO 2 /Si substrate. Understanding interlayer excitations will help in engineering excitonic devices and give an insight into the physics of many-body dynamics.

【 授权许可】

CC BY