Bottom-Up Synthesis of Carbon Quantum Dots With High Performance Photo- and Electroluminescence

Hong Hee Kim, Yeon Ju Lee, Chanho Park, Seunggun Yu, Sung Ok Won, Won Seon Seo, Cheolmin Park, Won Kook Choi

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3 Citations (Scopus)

Abstract

Although carbon quantum dots (CQDs) are of great interest because of cost effectiveness and environmental compatibility with the facile tunability of their optical properties, poor photo- and electroluminescence (EL) of CQDs limits further implementation. Here, a novel bottom-up synthetic route for fabricating highly crystalline CQDs suitable for high-brightness blue light-emitting diodes is demonstrated. The two-step solution process is based on time-controlled thermal carbonization of citric acid, followed by ligand exchange of the CQDs with oleylamine (OA) in solution. Carbonization allows for the nucleation and growth of crystalline CQDs, while OA treatment disperses the CQDs and stabilizes the solution, giving rise to CQDs with low structural defects and uniform sizes. The systematic study reveals the origin of the light emission of OA-treated CQDs by photoluminescence (PL) analysis, which yields a high quantum efficiency of ≈30%. The photoluminescence-optimized OA-treated CQDs exhibit excellent blue EL performance with a low turn-on voltage of ≈4 V and high brightness of 308 cd m−2; a negligible voltage-dependent color shift when they are employed to an inverted light-emitting diode.

Original languageEnglish
Article number1800080
JournalParticle and Particle Systems Characterization
Volume35
Issue number7
DOIs
Publication statusPublished - 2018 Jul

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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