Tunable Optical Properties of 2D Materials and Their Applications

Abstract

unlimited possibilities in the improvement of the performances of optoelectronic devices. [19-23] Beyond that, the properties of 2D materials can be tuned in situ by using different approaches [24-26] to expand the functionalities of optoelectronic devices. Out of them, the tunability in their optical properties has attracted great interest over the past decades where researchers dedicated to discovering various tuning methods to realize desired outcomes. [27,28] More excitingly, owing to the unprecedented electronic properties, high stretchability, magnetism, and thermal conductivity of 2D materials, different tuning approaches such as electrical gating, external strain stimuli, a static magnetic field, surface acoustic waves (SAWs), and thermal heating can be simultaneously adopted to participate the light-matter interaction, leading to the tailored and synergetic optical response of 2D materials. [29] Table 1 illustrates a brief advantages and weaknesses analysis between different optical tuning approaches of 2D and non-2D materials. There is a huge potential to revolutionize the optoelectronic devices by incorporating 2D materials with tunable optical properties. [30,31] So far, researchers have achieved flagship milestones in this area where a diverse set of high-performance optical devices are realized including modulators, photodetectors, optical sources, and optical switches. [32] In this review, we primarily focus on the theoretical and experimental researches of optical effects causing by various external stimuli in 2D materials. In Section 2, 2D materials with electro-optic effect and its application will be discussed, followed by piezophototronic effect and its application in Section 3. In Section 4, 2D materials with magneto-optic effect and its application will be discussed. Then, acousto-optic (AO) effect and its application, and thermo-optic (TO) effect and its application will be discussed in Sections 4 and 5, respectively. In the last section, the conclusion and perspective will be provided. 2. Electro-Optic Effect and Its Applications for 2D Materials 2.1. 2D Materials with Electro-Optic Effect In a broad sense, electro-optic effect is about an optical property change in the materials when applying an electric field. As shown in Figure 1, the refractive index of the material can be tuned in the presence of electric field due to the variation of charge carrier density. [29] This effect involves several Recent efforts have been heavily devoted to the development of next-generation optoelectronic devices based on 2D materials, due to their unique optical properties that are distinctly different from those of bulk counterparts. Given that the feature of flexible tunability is highly desired, various approaches have been demonstrated to efficiently modulate the optical properties, eventually enabling peculiar functionalities or realizing high-performance nanoscale devices. Here, this review focuses on recent advances in tuning the optical properties of 2D materials by external stimuli including elec...

Two-dimensional Graphitic Metal Carbides: A New Class of Atomically Thin Carbon-based Crystals

“…[18] Furthermore, the uncommon half-metals are considered to have extremely broad application prospects in the field of 2D spintronics such as spin filtering and spin transistors. [19] For the semiconducting ones, they can be used as thermoelectric materials, [20] light-emitting diodes, [21] and solar cells. [8a, 21] The list is by no means exhaustive, and the applications of the materials await further detailed studies.…”

A Review: Ion Transport of Two-Dimensional Materials in Novel Technologies from Macro to Nanoscopic Perspectives

“…Novel 2D materials are available with a wide range of applications. Because of their different crystalline structures and defects, these factors relate to specific band gap structures, of which some are suitable for optical absorption [143]. There have been reviews on the optical properties of 2D novel materials [143][144][145].…”

“…Because of their different crystalline structures and defects, these factors relate to specific band gap structures, of which some are suitable for optical absorption [143]. There have been reviews on the optical properties of 2D novel materials [143][144][145]. Bandgap energy properties and optical absorption for a whole spectrum span (Figure 18a) from insulators (e.g., hBN with 6 eV bandgap in a range of UV absorption), semiconductors (e.g., TMDs, MoS 2 with bandgap around 1.5-2.5 eV) are suited to visible light absorption in situations where black phosphorus occupies IR absorption with 0.3-2 eV bandgap) and semimetals (e.g., graphene with no bandgap) [144].…”

Advance Optical Properties and Emerging Applications of 2D Materials

“…Reviews exist on the discussion of linear optics, nonlinear optics, light-emitting, photodetection, and anisotropy in 2D materials, as shown in Figure 1 (Xia et al, 2014;Mak and Shan, 2016;Guo et al, 2019;. A recent review was published discussing the tunable properties of 2D materials (Ma et al, 2021). We have focused our discussion on graphene-based optical device applications.…”