In-plane anisotropic quantum confinement effect in ultrasmall SnS sheets

Abstract

Black phosphorus (BP) analogous tin(II) sulfide (SnS) has recently emerged as an attractive building block for electronic devices due to its highly anisotropic response. Two-dimensional (2D) SnS has shown to exhibit in-plane anisotropy in optical and electrical properties. However, the limitations in growing ultrasmall structures of SnS hinder the experimental exploration of anisotropic behavior in low dimension. Here, we present an elegant approach of synthesizing highly crystalline nanometer-sized SnS sheets. Ultrasmall SnS exhibits two distinct valleys along armchair and zig-zag directions due to in-plane structural anisotropy like bulk SnS. We show that in such SnS nanosheet dots, the band gaps corresponding to two valleys are increased due to quantum confinement effect. We particularly observe that SnS quantum dots (QDs) show excitation energy dependent photoluminescence (PL), which originates from the two nondegenerate valleys. Our work may open up an avenue to show the potential of SnS QDs for new functionalities in electronics and optoelectronics.

References in corpus (6)

• Purely in-plane ferroelectricity in monolayer SnS at room temperature
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• Quantum Nanophotonics in Two-Dimensional Materials
• Recent Advances in Two-Dimensional Metal Monochalcogenides
• In-plane anisotropic faceting of ultralarge and thin single-crystalline colloidal SnS nanosheets
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Cited by in corpus (2)

• Future prospect of anisotropic 2D tin sulfide (SnS) for emerging electronic and quantum device applications
• Advancements in Entangled Photon Pairs in 2D Van der Waals Materials for On-chip Quantum Applications