Dark exciton based strain sensing in tungsten-based transition metal dichalcogenides
Journal article, 2019

The recent emergence of atomically thin two-dimensional (2D) materials has opened up possibilities for the design of ultrathin and flexible nanoelectronic devices. As truly 2D materials, they exhibit an optimal surface-to-volume ratio, which results in an extremely high sensitivity to external changes which can not be achieved by conventional semiconductors. This makes these materials optimal candidates for sensing applications. Here, we propose a dark exciton based concept for ultrasensitive strain sensors. By investigating both dark and bright excitons in tungsten-based monolayer transition metal dichalcogenides, we demonstrate that the dark-bright-exciton separation can be controlled by strain, which has a crucial impact on the activation of dark excitonic states. The predicted opposite strain-induced shifts for dark and bright excitons result in a pronounced change in photoluminescence stemming from dark excitons even at very small strain values. The predicted high optical gauge factors of up to 8000 are promising for the design of optical strain sensors.

Author

Maja Feierabend

Chalmers, Physics, Condensed Matter Theory

Zahra Khatibi

Chalmers, Physics, Condensed Matter Theory

Iran University of Science and Technology

Gunnar Berghäuser

Chalmers, Physics, Condensed Matter Theory

Ermin Malic

Chalmers, Physics, Condensed Matter Theory

Physical Review B

24699950 (ISSN) 24699969 (eISSN)

Vol. 99 19 195454

Subject Categories

Textile, Rubber and Polymeric Materials

Other Physics Topics

Other Materials Engineering

DOI

10.1103/PhysRevB.99.195454

More information

Latest update

7/15/2019