title: Yellow-Emitting Carbon Nanodots and Their Flexible and Transparent Films for White LEDs.
abstract: We report carbon nanodots that can be utilized as effective color converting phosphors for the production of white light-emitting diodes (LEDs). Blue-excitable and yellow-emitting carbon nanodots, functionalized with 3-(imidazolidin-2-on-1-yl)propylmethyldimethoxysilane (IPMDS)-derived moieties (IS-CDs), are synthesized by a novel one-pot reaction in which the products from the initial reaction occurring between urea and 3-(2-aminoethylamino)propylmethyl-dimethoxysilane (AEPMDS) are further treated with citric acid. Distinctive from the majority of carbon nanodots reported previously, IS-CDs emit at 560 nm, under 460 nm excitation, with a quantum yield of 44%. Preliminary toxicity studies, assessed by the Artemia franciscana nauplii (brine shrimp larvae) bioassay, indicate that IS-CDs are largely nontoxic. Furthermore, the IS-CDs form flexible and transparent films without the need of encapsulating agents, and the solid films retain the optical properties of solvated IS-CDs. These features indicate an immense potential for the IS-CDs as an environmental-friendly, blue-excitable carbon nanodot-based phosphor in solid-state lighting devices.
authors.affiliation: Queensland Micro- and Nano-Technology Centre , 170 Kessels Road, Nathan, Queensland 4111, Australia.
authors.forename: Tak H
authors.initials: TH
authors.lastname: Kim
authors.forename: Alan R
authors.initials: AR
authors.lastname: White
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Sirdaarta
authors.affiliation: College of Physics, Jilin University , Changchun 130023, China.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Ji
authors.forename: Ian E
authors.initials: IE
authors.lastname: Cock
authors.forename: James
authors.initials: J
authors.lastname: St John
authors.forename: Sue E
authors.initials: SE
authors.lastname: Boyd
authors.affiliation: Queensland Micro- and Nano-Technology Centre , 170 Kessels Road, Nathan, Queensland 4111, Australia.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Brown
authors.affiliation: Queensland Micro- and Nano-Technology Centre , 170 Kessels Road, Nathan, Queensland 4111, Australia.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
keywords: carbon nanodots; organosilane; photoluminescence; solid-state nanomaterials; surface characterization; surface functionalization