Near-field spectroscopic imaging of exciton quenching at atomically sharp MoS2/WS2 lateral heterojunctions.
Nanoscale
; 14(17): 6323-6330, 2022 May 05.
Article
em En
| MEDLINE
| ID: mdl-35297443
ABSTRACT
Heterojunctions made by laterally stitching two different transition metal dichalcogenide monolayers create a unique one-dimensional boundary with intriguing local optical properties that can only be characterized by nanoscale-spatial-resolution spectral tools. Here, we use near-field photoluminescence (NF-PL) to reveal the narrowest region (105 nm) ever reported of photoluminescence quenching at the junction of a laterally stitched WS2/MoS2 monolayer. We attribute this quenching to the atomically sharp band offset that generates a strong electric force at the junction to easily dissociate excitons. Besides the sharp heterojunction, a model considering various widths of the alloying interfacial region under low or high optical pumping is presented. With a spatial resolution six times better than that of confocal microscopy, NF-PL provides an unprecedented spectral tool for non-scalable 1D lateral heterojunctions.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article