標題: Tailoring fluorescence emissions, quantum yields, and white light emitting from nitrogen-doped graphene and carbon nitride quantum dots
作者: Gu, Siyong
Hsieh, Chien-Te
Gandomi, Yasser Ashraf
Li, Jianlin
Yue, Xing Xing
Chang, Jeng-Kuei
材料科學與工程學系
Department of Materials Science and Engineering
公開日期: 21-Sep-2019
摘要: Highly fluorescent N-doped graphene quantum dots (NGQDs) and graphitic carbon nitride quantum dots (CNQDs, g-C3N4) were synthesized using a solid-phase microwave-assisted (SPMA) technique. The SPMA method, based on the pyrolysis of citric acid and urea with different recipes, is capable of producing quantum dots with coexisting NGQDs and CNQDs at 280 degrees C within only five minutes. The photoluminescence (PL) emissions from NGQD and CNQDs are strongly dependent on the excitation wavelength and the solvent type, i.e., water, ethanol, and N-methyl pyrrolidinone. The unique attribute of the quantum dots, possessing a multiple chromophoric band-gap structure, originates from the presence of g-C3N4, defect-related emissive traps, and grain boundaries. Thus, an appropriate excitation wavelength induces a conjugated pi electron system to fulfill the most probable absorption band, resulting in wavelength-dependent emissions including ultraviolet, visible and infrared light. The quantum yield of the NGQD and CNQD samples can reach as high as 68.1%. Accordingly, a light-emitting device using the combination of the NGQD and CNQD powder embedded polymeric film can emit white-like light with ultra-high power-conversion efficiency.
URI: http://dx.doi.org/10.1039/c9nr05422g
http://hdl.handle.net/11536/152780
ISSN: 2040-3364
DOI: 10.1039/c9nr05422g
期刊: NANOSCALE
Volume: 11
Issue: 35
起始頁: 16553
結束頁: 16561
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