Demonstration of a White Laser with V₂C MXene‐Based Quantum Dots

Abstract

grown as the white laser gains [12][13][14][15] and some approaches have been developed for constructing the prerequisite optical feedback "cavity" with the goal of simultaneous RGB or RYGB lasing. [10,11,13,14] However, constrained by the compactness, difficulty in growth or wavelength control, or the environment friendly, the white lasers are still underdeveloped, and the available materials and approaches are still being extensively sought.In recent years, an emerging family of 2D nanomaterials, group of early transition metal carbides and/or carbonitrides labeled MXenes, was developed by selectively etching MAX phases, [16,17] where M represents an early transition metal, A denotes a main group of 3 or 4 elements, and X is either carbon or nitrogen. They have exhibited super chemical, physical, and environmental properties distinguishing from traditional 2D materials, e.g., they possess hydrophilic surface with metallic conductivity, excellent chemical stability, superior electrical conductivity, environmentally friendly characteristics, etc. [18][19][20][21][22] Unfortunately, their intrinsic photoluminescence response is low, which limits their optical and even further biological applications. The formation of quantum dots (QDs) would generally enhance their photoluminescence by means of the quantum confinement and edge effects, which has been recently experimentally realized in Ti 3 C 2 MXene QDs with the wavelength range from about 350 nm (violet) to 600 nm (orange-red). [23,24] Therefore, it can be believed that the 2D MXenes should be excellent white laser gain medium if the gain can be further enhanced especially in the red range and a broadband optical feedback "cavity" can be constructed. Associated with the theory of a finite atomic system, the sensitivity of the electronic states density of the QDs, corresponding to their photoluminescence, is dependent on their sizes due to the Coulomb blockade effect, [25][26][27] which indicated that the MXene quantum systems with fewer atom layers structure should be more susceptible to the same external passivation and should have better passivation effect than those MXenes with more atom layers structure. For MXene materials, their unique structural characteristics determine that they have at least three-atom layered structure, which indicates that the V 2 C MQDs with fewest atom layers should possess enhanced and broadened photoluminescence after passivation. Considering the optical feedback, effective Multicolor photoluminescence over the full visible color spectrum is critical in many modern science and techniques, such as full-color lighting, displays, biological and chemical monitoring, multiband communication, etc., but the ultimate white lasing especially on the nanoscale is still a challenge due to its exacting requirements in the balance of the gain and optical feedback at different wavelengths. Recently, 2D transition metal carbides (MXenes) have emerged, with some superior chemical, physical, and environmental properties distinguishing them from tr...

2D Material Optoelectronics for Information Functional Device Applications: Status and Challenges

“…[ 95 ] The obtained emission frequency has well covered the visible regime, and white random laser using V 2 C MXene QDs has recently been realized, as shown in Figure 6d. [ 92 ]…”

“…[ 96 ] Copyright 2018, Royal Society of Chemistry, and the emerging of the random laser as the increase of pump power (right), Reproduced with permission. [ 92 ] Copyright 2019, Wiley‐VCH.…”

Mechanically Induced Shaping of Organic Single Crystals: Facile Fabrication of Fluorescent and Elastic Crystal Fibers

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Emission Color Manipulation in Transparent Nanocrystals‐in‐Glass Composites Fabricated by Solution‐Combustion Process

“…Multicolor or multi‐wavelength solid‐state light sources with photoluminescence covering the full visible spectrum have attracted growing attention in diverse fields, not only for color‐demanded areas including light‐emitting device and full‐color displays, but also for their potential applications in advanced technologies ranging from coherent lasers to optical communication, from data storage to biophotonics . Combining two or three of the red, green, and blue (RGB) emission is a typical strategy to produce multicolor, especially for white light generation .…”