Innovations in the Solid‐State Fluorescence of Carbon Dots: Strategies, Optical Manipulations, and Applications

Abstract

Carbon dots (CDs)—carbon nanoparticles smaller than 10 nm—have attracted widespread attention owing to their excellent optical properties. However, high‐performing CDs often suffer from severe aggregation‐induced quenching in the solid state, which limits their commercial applicability. Therefore, CD materials with efficient solid‐state luminescence are sought. As research on the structure and photoluminescence mechanisms of CDs has intensified in recent years, strategies to construct fluorescent solid‐state CD materials and tune their emissions have broadened. This article reviews recent advances in the strategies and mechanisms for attaining solid‐state fluorescence in CDs, describes specific ways to tune the optical properties of this fluorescence, introduces the latest applications of the resulting CDs to optoelectronics, biology, and sensing, and finally considers the prospects for future application and current challenges facing the development of solid‐state fluorescence in CDs.

The emergence and prospects of carbon dots with solid-state photoluminescence for light-emitting diodes

“…There have been already a number of excellent reviews focusing on different aspects of photoluminescent CDs, such as their synthesis, luminescence mechanism, optical property regulation and optoelectronic applications. 13,37–41 However, only a very limited number of review articles have focused on SSCDs and their related applications. In this review, with the aim of promoting better SSCD engineering and their further development, we primarily update the latest significant developments on SSCDs, including synthesis, classification such as fluorescent SSCDs, phosphorescent SSCDs, delay fluorescent SSCDs, and their recent advances in LEDs, as illustrated in Fig.…”

Surface Modification Functionalized Carbon Dots

“…Researchers have sought to optimize the preparation of CDs, modify their surfaces, modulate their performance, and explore innovative applications. Many major breakthroughs have been made in recent years, including the development of multicolor, deep red, and near-infrared emission, [7][8][9][10][11] narrow emission wavelength ranges, [12][13][14] solid-state fluorescence, [15][16][17] two-or multi-photon photoluminescence (PL), [18] chirality, [19] room-temperature phosphorescence, [20] and thermally activated delayed fluorescence. [21,22] CDs usually refers to a class of zero-dimensional carbon particles less than 10 nm in size, whose structure is composed of carbon core with different crystallinity and various functional groups on the surface.…”

Construction of Carbon Dots@LiCl‐polyacrylamide with Humidity‐Induced Ultralong Room‐Temperature Phosphorescence to Fluorescence and Rigid‐to‐Flexible Transition Behavior

“…[ 65–68 ] Several composite polymer films with tunable RTP properties have been obtained. [ 69–71 ] Therefore, doping CDs into stimuli‐responsive polymers can potentially realize synchronous responses of the polymer and CDs under the same stimulus.…”