High-efficiency and narrow-band near-ultraviolet carbon dots for high-color-purity light-emitting diodes

Junkai Ren; Menghong Li; Dan Qu; Jiaolong Liu; Bing Wei; Jia Wang

doi:10.1016/j.jcis.2025.138293

High-efficiency and narrow-band near-ultraviolet carbon dots for high-color-purity light-emitting diodes

J Colloid Interface Sci. 2025 Jun 27;699(Pt 2):138293. doi: 10.1016/j.jcis.2025.138293. Online ahead of print.

Authors

Junkai Ren¹, Menghong Li², Dan Qu³, Jiaolong Liu⁴, Bing Wei³, Jia Wang⁵

Affiliations

¹ School of Physics, Xidian University, No. 2 Taibai South Road, Xi'an 710071, China. Electronic address: renjunkai@xidian.edu.cn.
² Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, No. 98 Xiwu Road, Xi'an 710004, China.
³ School of Physics, Xidian University, No. 2 Taibai South Road, Xi'an 710071, China.
⁴ School of Physics, Xidian University, No. 2 Taibai South Road, Xi'an 710071, China. Electronic address: liujiaolong@xidian.edu.cn.
⁵ Department of Physics, Umeå University, Linnaeus väg 24, Umeå SE-90187, Sweden; Wallenberg Initiative Materials Science for Sustainability, Department of Physics, Umeå University, Umeå SE-90187, Sweden. Electronic address: jia.wang@umu.se.

PMID: 40602281
DOI: 10.1016/j.jcis.2025.138293

Abstract

Near-ultraviolet (NUV) light is critical for applications in lighting, manufacturing, and medical fields, yet existing NUV emitters often suffer from complex syntheses or rely on toxic or unsustainable materials. Herein, we present a facile solvothermal synthesis of high-efficiency, narrow-band NUV-emitting carbon dots (NUV-CDs) derived from bio-derivable phloroglucinol. These NUV-CDs exhibit a sharp emission peak at 403 nm with a high photoluminescence quantum yield (PLQY) of 60 % and a narrow full width at half maximum (FWHM) of 35 nm in ethanol solution. Structural and spectroscopic analyses reveal that the NUV-CDs are formed through dehydration and dehydrogenation reactions, resulting in a single type of emissive center with weak environmental interactions. When integrated into a polyvinyl alcohol (PVA) matrix and applied as a light-conversion coating on a UV-LED chip, the resulting device emits at 408 nm with an FWHM of 50 nm and an exceptional color purity of 87.7 %. This study offers a promising, environmentally friendly alternative for high-performance NUV light sources, complementing the spectral gap of existing CD materials.

Keywords: Carbon dots; High color purity; Light-emitting diodes; Near-ultraviolet.