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Abstract Thin ferroelectric materials hold great promise for compact nonvolatile memory and nonlinear optical and optoelectronic devices. Herein, an ultrathin in‐plane ferroelectric material that exhibits a giant nonlinear optical effect, group‐IV monochalcogenide SnSe, is reported. Nanometer‐scale ferroelectric domains with ≈90°/270° twin boundaries or ≈180° domain walls are revealed in physical‐vapor‐deposited SnSe by lateral piezoresponse force microscopy. Atomic structure characterization reveals both parallel and antiparallel stacking of neighboring van der Waals ferroelectric layers, leading to ferroelectric or antiferroelectric ordering. Ferroelectric domains exhibit giant nonlinear optical activity due to coherent enhancement of second‐harmonic fields and the as‐resulted second‐harmonic generation was observed to be 100 times more intense than monolayer WS2. This work demonstrates in‐plane ferroelectric ordering and giant nonlinear optical activity in SnSe, which paves the way for applications in on‐chip nonlinear optical components and nonvolatile memory devices.
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Self-limiting stoichiometry in SnSe thin films
Raman spectroscopy showing the initial formation of SnSe2followed by the stabilization of SnSe with increased growth time.
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- PAR ID:
- 10504525
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Nanoscale
- Volume:
- 15
- Issue:
- 23
- ISSN:
- 2040-3364
- Page Range / eLocation ID:
- 9973 to 9984
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d3nr00645j
