scholarly journals Towards Red Emissive Systems Based on Carbon Dots

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2089
Author(s):  
Spyridon Gavalas ◽  
Antonios Kelarakis
Keyword(s):  
Photodynamic Therapy ◽  
Polymer Nanocomposites ◽  
Surface Functionalization ◽  
Carbon Dots ◽  
Excitation Wavelength ◽  
High Quantum Yield ◽  
Heteroatom Doping ◽  
Light Emitting ◽  
Effective Strategies ◽  
Pl Emission

Carbon dots (C-dots) represent an emerging class of nontoxic nanoemitters that show excitation wavelength-dependent photoluminescence (PL) with high quantum yield (QY) and minimal photobleaching. The vast majority of studies focus on C-dots that exhibit the strongest PL emissions in the blue/green region of the spectrum, while longer wavelength emissions are ideal for applications such as bioimaging, photothermal and photodynamic therapy and light-emitting diodes. Effective strategies to modulate the PL emission of C-dot-based systems towards the red end of the spectrum rely on extensive conjugation of sp2 domains, heteroatom doping, solvatochromism, surface functionalization and passivation. Those approaches are systematically presented in this review, while emphasis is given on important applications of red-emissive suspensions, nanopowders and polymer nanocomposites.

Multicolor tunable highly luminescent carbon dots for remote force measurement and white light emitting diodes

2019 ◽  
Vol 55 (81) ◽  
pp. 12164-12167 ◽  
Author(s):  
Ya Liu ◽  
Miaoran Zhang ◽  
Yanfen Wu ◽  
Rui Zhang ◽  
Yi Cao ◽  
...  
Keyword(s):  
Quantum Yield ◽  
White Light ◽  
Carbon Dots ◽  
Light Emitting Diodes ◽  
Solvothermal Method ◽  
Force Measurement ◽  
High Quantum Yield ◽  
Light Emitting ◽  
One Step ◽  
White Light Emitting Diodes

A one-step solvothermal method was exploited to synthesize blue, yellow and red carbon dots with high quantum yield by altering the corresponding reaction solvent.

Understanding the Photoluminescence Mechanism of Carbon Dots

MRS Advances ◽  
2017 ◽  
Vol 2 (51) ◽  
pp. 2927-2934 ◽  
Author(s):  
Zhoufeng Jiang ◽  
Marta J. Krysmann ◽  
Antonios Kelarakis ◽  
Petr Koutnik ◽  
Pavel Anzenbacher ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Quantum Yields ◽  
Excitation Wavelength ◽  
Time Resolved ◽  
Light Emitting ◽  
Dependent Component ◽  
Different Types ◽  
Photoluminescence Mechanism ◽  
Time Resolved Photoluminescence ◽  
Absolute Quantum

ABSTRACTThe carbon dots were investigated to reveal their light-emitting mechanism. The fluorescence spectra of carbon dots show typically two different types of photoluminescence: the excitation-independent component in the short wavelength, and the excitation-dependent component in the longer wavelength. The UV-Vis spectrum of carbon dots shows the absorption maximum of 340 nm which should be accredited to the n-π* transition of the carbonyl group in carbon dots. Absolute quantum yields of carbon dots dispersed in Polyvinyl alcohol is around 15% when the excitation wavelength is less than 425 nm, but decreases continuously when the excitation wavelength increases. The decay lifetimes of the carbon dots also show an abrupt change at excitation wavelength 425 nm. Time resolved photoluminescence was implemented from 31K to 291K to study the photoluminescence decay dynamics of carbon dots, resulting in the continuously decreasing of the lifetime as the temperature increases.

Lanthanide based white-light-emitting hydrogel mediated by fluorescein and carbon dots with high quantum yield and multi-stimuli responsiveness

2020 ◽  
Vol 8 (10) ◽  
pp. 3380-3385 ◽  
Author(s):  
Juan Xue ◽  
Xihan Xu ◽  
Yi Zhu ◽  
Dayong Yang
Keyword(s):  
Quantum Yield ◽  
White Light ◽  
Carbon Dots ◽  
Light Emission ◽  
White Light Emission ◽  
High Quantum Yield ◽  
Light Emitting ◽  
High Quantum ◽  
Multiple Stimulus

A WLE hydrogel simultaneously possessing high quantum yield (18.00%) and multiple stimulus responsiveness is designed and synthesized. Our work provides a straightforward strategy to prepare smart white-light emission hydrogels.

Color Emission Carbon Dots with Quench-ResixAstant Solid-State Fluorescence for Light-Emitting Diodes

2021 ◽  
Vol 9 (10) ◽  
pp. 3901-3908
Author(s):  
Fanyong Yan ◽  
Hao Zhang ◽  
Jinxia Xu ◽  
Yawei Wu ◽  
Yueyan Zang ◽  
...  
Keyword(s):  
Solid State ◽  
Carbon Dots ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Solid State Fluorescence ◽  
Color Emission

Superior Stable and High Quantum Yield Phosphor Na2BaSr(PO4)2: Eu2+ for Plant Growth LEDs

2021 ◽  
Author(s):  
Jinmeng Xiang ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
Minkun Jin ◽  
Xue Zhou ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Plant Growth ◽  
Light Emitting Diodes ◽  
Light Environment ◽  
High Quantum Yield ◽  
Light Emitting ◽  
Growth Rhythm ◽  
High Quantum ◽  
Violet Light ◽  
Important Means

Controlling the light environment of plant growth using phosphor-converted light-emitting diodes (pc-LEDs) is an important means to regulate the growth rhythm and enhance the yield, in which bluish violet light...

scholarly journals In Vitro Effect of Photodynamic Therapy with Different Lights and Combined or Uncombined with Chlorhexidine on Candida spp.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta
Keyword(s):  
Photodynamic Therapy ◽  
Light Emitting Diode ◽  
Antimicrobial Effect ◽  
Photodynamic Treatment ◽  
Candida Spp ◽  
Promising Alternative ◽  
Light Emitting ◽  
Colony Forming Units ◽  
Vitro Effect

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.

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