Drift-dominant exciton funneling and trion conversion in 2D semiconductors on the nanogap.
Sci Adv
; 8(5): eabm5236, 2022 Feb 04.
Article
en En
| MEDLINE
| ID: mdl-35119920
ABSTRACT
Understanding and controlling the nanoscale transport of excitonic quasiparticles in atomically thin two-dimensional (2D) semiconductors are crucial to produce highly efficient nano-excitonic devices. Here, we present a nanogap device to selectively confine excitons or trions of 2D transition metal dichalcogenides at the nanoscale, facilitated by the drift-dominant exciton funneling into the strain-induced local spot. We investigate the spatiospectral characteristics of the funneled excitons in a WSe2 monolayer (ML) and converted trions in a MoS2 ML using hyperspectral tip-enhanced photoluminescence imaging with <15-nm spatial resolution. In addition, we dynamically control the exciton funneling and trion conversion rate by the gigapascal-scale tip pressure engineering. Through a drift-diffusion model, we confirm an exciton funneling efficiency of â¼25% with a significantly low strain threshold (â¼0.1%), which sufficiently exceeds the efficiency of â¼3% in previous studies. This work provides a previously unexplored strategy to facilitate efficient exciton transport and trion conversion of 2D semiconductor devices.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Sci Adv
Año:
2022
Tipo del documento:
Article