Polarization-Controllable Plasmonic Enhancement on the Optical Response of Two-Dimensional GaSe Layers

Abstract

Resonant plasmonic coupling has been considered as a promising strategy to enhance the optical response and manipulate the polarization of two-dimensional (2D) layer materials toward the practical applications. Here, a hybrid structure with periodic Ag nanoprism arrays was designed and fabricated on 2D GaSe layers to enhance these optical properties. By using the optimized hybrid structure with well-matched resonance, significant enhanced Raman scattering and band edge emission were successfully realized, and it is also interestingly found that the higher enhancement would be achieved while decreasing the thickness of GaSe layers. Theoretical simulation indicated that the strongly enhanced local field and the modified charge densities are the main reasons. By further introducing the patterned gratings on the plasmonic hybrid structure, selective excitation with controllable polarization was readily realized, besides the strongly enhanced photoluminescence intensity. This work provides a strategy for the plasmonic engineering of polarization controllable 2D optoelectronic devices.

Review of Anisotropic 2D Materials: Controlled Growth, Optical Anisotropy Modulation, and Photonic Applications

“…To address this issue, micropatterned gratings composed of plasmonic materials were developed (Figure 9d). As is reported by Wan et al [213] Ag nanoprism gratings were designed on the GaSe layer, where the strongly enhanced local field and the modified charge densities resulted in selective excitation with controllable polarization (9.3% linear polarization) (Figure 9e,f), in addition to the strongly enhanced PL intensity (20 times).…”

“…d) The SEM image of GaSe integrated with Ag nanoprism gratings, and the linear polarized PL spectrum of e) GaSe/normal Ag and f) GaSe/Ag nanoprism gratings. (d-f) Reproduced with permission [213]. Copyright 2019, American Chemical Society.…”

Space‐Confined Growth of 2D InI Showing High Sensitivity in Photodetection

“…In the inset is the PL mapping verifying the high invariability over the entire flake. [ 29 ] To investigate the chemical composition of the as‐grown InI flake, high‐resolution mapping is analyzed using an electron probe microanalyzer (EPMA). A relatively good distribution of In‐ and I‐atoms in almost a 1:1 ratio is observed (Figure 1g,h).…”

Exciton–Photonics: From Fundamental Science to Applications

“…(194,195) Therefore, tip-enhanced near-field spectroscopy or coupling with plasmonic arrays can offer a viable strategy towards enhancing Raman or PL signals from these materials. (156,196) In this regard, a recent study reported estimating phonon correlation lengths (Lc) of 50-60 nm in few-layered GaS with plasmonic Au tip (Figure 4g). ( 156) Lc was measured by collecting the Raman spectrum as a function of tip-sample distance.…”

“…Aside from TMDCs of Mo, W, and GNRs, groups III–VI layered semiconductors MX (M = Ga and In; X = S, Se and Te) are also important members of the layered materials family, showing relatively large optical band gaps for monolayers (∼2.5–3.0 eV). , These large optical band gaps have attracted their use in applications such as blue light-emitting diodes . However, low emission efficiencies and weak Raman signals in monolayers present challenges in investigating them via far-field spectroscopic techniques. , Therefore, tip-enhanced near-field spectroscopy or coupling with plasmonic arrays can offer a viable strategy toward enhancing Raman or PL signals from these materials. , In this regard, a recent study reported estimating phonon correlation lengths ( L c ) of 50–60 nm in few-layered GaS with a plasmonic Au tip (Figure G) …”