Exciton engineering with 2D heterostructures.
Tutor / Supervisor
Koppens, Frank H. L.
Student
Moreno Abajo, Álvaro
Document type
Master thesis
Date
2020
rights
Open Access
Publisher
Universitat Politècnica de Catalunya
UPCommons
Abstract
Quantum emitters have an important role in many quantum technologies as quantum sensing and metrology, quantum computation or quantum information. They must be isolated from their environment, but paradoxically some external control is desired to be kept as well. Those requirements meet in 2D-materials like TMDs. Excitons, bound electron-hole pairs, are sensitive to their dielectric environment and to external electric fields due to the low dimensionality of 2D-material, making possible to modulate their energy landscape by patterning the adjacent materials geometry, which could allow exciton confinement. In this work, we have first simulated electrostatic fields in patterned hBN and nano-porous graphene (NPG) structures. Field is concentrated in the edges, creating an in-plane field that shift the exciton energy due to quantum confined Stark effect. Potential wells created could lead even to room temperature confinement. Secondly, we have performed PL measurements that point out spatio-temporal correlations in exciton emission that could be related with exciton diffusion. Also, we have shown that NPG decreases exciton diffusion, proving therefore an external modulation of the exciton energy landscape.
Participating teacher
- Koppens, Frank H. L.