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Title: Luminescent carbon quantum dots with high quantum yield as a single white converter for white light emitting diodes

Carbon quantum dots (CQDs) with high quantum yield (51.4%) were synthesized by a one-step hydrothermal method using thiosalicylic acid and ethylenediamine as precursor. The CQDs have the average diameter of 2.3 nm and possess excitation-independent emission wavelength in the range from 320 to 440 nm excitation. Under an ultraviolet (UV) excitation, the CQDs aqueous solutions emit bright blue fluorescence directly and exhibit broad emission with a high spectral component ratio of 67.4% (blue to red intensity to total intensity). We applied the CQDs as a single white-light converter for white light emitting diodes (WLEDs) using a UV-LED chip as the excitation light source. The resulted WLED shows superior performance with corresponding color temperature of 5227 K and the color coordinates of (0.34, 0.38) belonging to the white gamut.
Authors:
; ;  [1] ;  [2] ; ; ;  [1] ;  [2]
  1. Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China)
  2. (China)
Publication Date:
OSTI Identifier:
22486130
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AQUEOUS SOLUTIONS; CARBON; COLOR; EXCITATION; FLUORESCENCE; HYDROTHERMAL SYNTHESIS; LIGHT EMITTING DIODES; PRECURSOR; QUANTUM DOTS; TEMPERATURE RANGE OVER 4000 K; ULTRAVIOLET RADIATION; VISIBLE RADIATION; WAVELENGTHS; YIELDS