Nonvolatile Control of Valley Polarized Emission in 2D WSe 2 -AlScN Heterostructures.

Autor:	Singh S; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.; Department of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands., Kim KH; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Jo K; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Musavigharavi P; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.; Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32816, United States., Kim B; Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Zheng J; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Trainor N; Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16801, United States., Chen C; 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16801, United States., Redwing JM; Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16801, United States.; 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16801, United States., Stach EA; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Olsson RH 3rd; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Jariwala D; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Jazyk:	angličtina
Zdroj:	ACS nano [ACS Nano] 2024 Jul 09; Vol. 18 (27), pp. 17958-17968. Date of Electronic Publication: 2024 Jun 25.
DOI:	10.1021/acsnano.4c04684
Abstrakt:	Achieving robust and electrically controlled valley polarization in monolayer transition metal dichalcogenides (ML-TMDs) is a frontier challenge for realistic valleytronic applications. Theoretical investigations show that the integration of 2D materials with ferroelectrics is a promising strategy; however, an experimental demonstration has remained elusive. Here, we fabricate ferroelectric field-effect transistors using a ML-WSe 2 channel and an Al 0.68 Sc 0.32 N (AlScN) ferroelectric dielectric and experimentally demonstrate efficient tuning as well as non-volatile control of valley polarization. We measure a large array of transistors and obtain a maximum valley polarization of ∼27% at 80 K with stable retention up to 5400 s. The enhancement in the valley polarization is ascribed to the efficient exciton-to-trion (X-T) conversion and its coupling with an out-of-plane electric field, viz., the quantum-confined Stark effect. This changes the valley depolarization pathway from strong exchange interactions to slow spin-flip intervalley scattering. Our research demonstrates a promising approach for achieving non-volatile control over valley polarization for practical valleytronic device applications.
Databáze:	MEDLINE
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