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Luminescent solar concentrators (LSCs) are attractive for the easy operation and high compatibility with building integrated photovoltaics due to their low cost, large-scale and applicability. However, underutilized sunlight in visible wavelengths often impedes the advance of LSCs. Here, we demonstrate an orange-emitting carbon nanodots-based LSC (O-CDs) with excitation concentrated in the visible wavelengths. The orange-emitting carbon nanodots (O-CDs) with highly localized excitonic emission are prepared via atomic condensation of doped pyrrolic nitrogen, delivering a high photoluminescence quantum yield of 80 % and a suitable Stokes shift with absorption spectrum situated in the visible region. The O-CDs are embedded in polyvinylpyrrolidone to obtain a highly transparent, stable and environmentally friendly O-CDs-based LSC. Thanks to efficient utilization of solar radiation in visible areas and well match between the emission of O-CDs and the response bands of photovoltaic cells, the O-CDs-based LSC reveals an optical conversion efficiency of 5.17 %, superior to that of most carbon nanodots-based LSCs. These results provide an effective strategy to develop carbon-based luminescent concentrated materials for architectural integrated photovoltaic technology.

As one promising carbon‐based material, sp3‐hybrid carbon nitride has been predicted with various novel physicochemical properties. However, the synthesis of sp3‐hybrid carbon nitride is still limited by the nanaoscale, low crystallinity, complex source, and expensive instruments. Herein, we have presented a facile approach to the sp3‐hybrid carbon nitride nano/micro‐crystals with microwave‐assisted confining growth and liquid exfoliation. Actually, the carbon nitride nano/micro‐crystals can spontaneously emerge and grow in the microwave‐assisted polymerization of citric acid and urea, and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/micro‐crystals. The obtained carbon nitride nano/micro‐crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96% in ethanol and 18.05% in solid state. The experimental characterizations and density functional theory calculations reveal that the interface‐trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro‐crystals and the interparticle staggered stacking will prevent the aggregation‐caused‐quenching partially. Finally, the carbon nitride nano/micro‐crystals are demonstrated to be potentially useful as the phosphor medium in light‐emitting‐diode for interrupting blue light‐induced eye damage. This work paves new light on the synthesis strategy of sp3‐hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have attracted much attention because of their unique structures and fascinating optical properties. In recent years, multicolor CDs have been realized through the efforts of researchers. However, it remains a challenge to obtain CDs with photoluminescence (PL)-afterglow dual-mode white emission, which limits the application of CDs in the field of light emitting diodes (LEDs). Herein, an effective strategy is designed to prepare both white PL and afterglow CDs (w-CDs), which is to combine (3-aminopropyl)triethoxysilane (APTES) and orange fluorescence CDs (o-CDs) as precursors through a hydrothermal reaction. During the synthesis of w-CDs, blue room temperature phosphorescence (RTP) CDs (b-CDs) formed using APTES were used as donors and o-CDs as acceptors. Depending on triplet-to-singlet Förster resonance energy transfer (FRET), dual-mode white light CDs with Commission Internationale de l'Eclairage (CIE) coordinates of (0.37, 0.37) for PL and (0.33, 0.37) for afterglow, and a PL quantum yield (PLQY) of 32.44% were successfully prepared. Importantly, by changing the ratio of o-CDs to b-CDs, the color temperature of the white afterglow can be easily adjusted from cold white to warm white. In addition, w-CDs have been successfully used in the fabrication of white LEDs (WLEDs) and dynamic displays, and can be applied to time-delay illumination and afterglow display. [ABSTRACT FROM AUTHOR]

Persistent mechanoluminescence (PML) is highly desirable for its ability to overcome transient‐emitting behavior, but its applications are hindered by the limited emission wavelengths. Herein, a universal chemical interlinkage‐assisted efficient energy transfer (ET) strategy is introduced to achieve color conversion from green to red in traditional PML materials. A straightforward chemical route to create the RhB@SiO2/SAOED system is established via covalent chemical interlinkage by depositing mesoporous silica‐encapsulated Rhodamine B (RhB) nanoparticles (RhB@SiO2) onto SrAl2O4:Eu, Dy (SAOED) particles. The resulting system exhibits a high ET efficiency of 53.5%. The multicolor PML of the RhB@SiO2/SAOED system remains visible to the naked eye for exceeding 28 s after mechanical stimulation. With this unique PML behavior, the RhB@SiO2/SAOED system demonstrates the potential applications ranging from visualized reading activities to multi‐mode anticounterfeiting. This universal PML color‐conversion strategy provides a new approach to high‐performance mechanical light energy‐conversion systems and may further inspire more diverse functional applications of classical PML materials. [ABSTRACT FROM AUTHOR]