Valley-selective carrier transfer in SnS-based van der Waals heterostructures.
Nanoscale Horiz
; 9(10): 1823-1832, 2024 Sep 23.
Article
en En
| MEDLINE
| ID: mdl-39171396
ABSTRACT
Valleytronics, i.e., use of the valley degree of freedom in semiconductors as an information carrier, is a promising alternative to conventional approaches for information processing. Transition metal dichalcogenides with degenerate K/K' valleys have received attention as prototype 2D/layered semiconductors for valleytronics, but these systems rely on exotic effects such as the valley-Hall effect for electrical readout of the valley occupancy. Non-traditional valleytronic systems hosting sets of addressable non-degenerate valleys could overcome this limitation. In the van der Waals semiconductor Sn(II) sulfide (SnS), for instance, different bandgaps and band edges may allow manipulating the population of the X- and Y-valleys via charge transfer across interfaces to other layered semiconductors. Here, we establish this concept by comparing SnS flakes and SnS-based heterostructures. Cathodoluminescence spectroscopy shows a striking reversal of the luminescence intensity of the two valleys in SnS-GeS van der Waals stacks, which stems from a selective electron transfer from the Y-valley into GeS while X-valley electrons remain confined to SnS. Our results suggest that non-traditional systems, embodied here by SnS-based van der Waals heterostructures, open avenues for valley-selective readout relying on design parameters such as heterostructure band offsets that are among the core concepts of semiconductor technology.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Nanoscale Horiz
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido