Electrostatically Tunable Near‐Infrared Plasmonic Resonances in Solution‐Processed Atomically Thin NbSe₂

Abstract

In the broad spectral range, near‐infrared (NIR) plasmonics find applications in telecommunication, energy harvesting, sensing, and more, all of which would benefit from an electrostatically controllable NIR plasmon source. However, it is difficult to control bulk NIR plasmonics directly with electrostatics because of the strong electric‐field screening effect and high carrier concentration required to support NIR plasmons. Here, this constraint is overcome and the observation of NIR plasmonic resonances that can be modulated electrostatically over a range of ≈360 cm–1 in few‐layer NbSe2 gratings is reported, thanks to the enhanced electrostatics of atomically thin 2D materials and the high‐quality film produced by a solution method. NbSe2 plasmons also render strong field confinement due to their atomic thickness and provide an extra degree of resonance frequency modulation from the layered structure. This study identifies metallic 2D materials as promising (easily produced and well‐performing) candidates to extend electrostatically tunable plasmonics to the technologically important NIR range.

Abnormal linear dichroism transition in two-dimensional PdPS

“…4a. 24,25 As the thickness increases, red shifts of ∼3 and ∼2 cm −1 were evidently observed for the peak positions of 102 and 489 cm −1 , respectively, indicating the strong interlayer coupling of PdPS shown in Fig. 4b and c.…”

Tunability of the Superconductivity of NbSe2 Films Grown by Two-Step Vapor Deposition

“…In turn, the superconducting transition critical temperature ( T c , the temperature where the sheet resistance drops to 10% of its normal state) is an important parameter to evaluate the crystallization quality of a 2D superconductor. Many methods have been developed to improve the crystalline quality of superconducting few-layer NbSe 2 , for example: (a) exfoliation from bulk single-crystal NbSe 2 by the electrochemical exfoliation method [ 25 , 26 , 27 , 28 , 29 ]; (b) growth by salt-assisted CVD [ 22 , 30 , 31 ]; (c) growth by molecular beam epitaxy (MBE) under ultra-high vacuum [ 20 , 32 , 33 ]; and (d) growth of a wafer-scale NbSe 2 film in oxygen-free conditions by a two-step vapor deposition method [ 23 ]. However, most of the above preparations of NbSe 2 have either a lot of point defects or a small grain size, which reduces its environmental stability or T c .…”

Impact of Large Gate Voltages and Ultrathin Polymer Electrolytes on Carrier Density in Electric-Double-Layer-Gated Two-Dimensional Crystal Transistors

“…This gating mechanism induces high sheet carrier densities (10 13 –10 14 cm –2 ) in various organic and inorganic semiconductors. , EDL gating is also used in fundamental research of low-dimensional materials. For example, this technique has been effective in controlling light scattering and emission, , surface plasmon resonance, ,, and the transition temperature for superconductivity ,, in layered materials including graphene, 2D metals, and transition-metal dichalcogenides (TMDs).…”