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

Journal Article · Mon Nov 23 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4936234· OSTI ID:22486130

Feng, X. T.; Zhang, Y.; Zhang, F.; Wang, Y. L.

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.

• OSTI ID: 22486130
• Journal Information: Applied Physics Letters, Vol. 107, Issue 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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