title: Control of Photoluminescence of Carbon Nanodots via Surface Functionalization using Para-substituted Anilines.
abstract: Carbon nanodots (C-dots) are a kind of fluorescent carbon nanomaterials, composed of polyaromatic carbon domains surrounded by amorphous carbon frames, and have attracted a great deal of attention because of their interesting properties. There are still, however, challenges ahead such as blue-biased photoluminescence, spectral broadness, undefined energy gaps and etc. In this report, we chemically modify the surface of C-dots with a series of para-substituted anilines to control their photoluminescence. Our surface functionalization endows our C-dots with new energy levels, exhibiting long-wavelength (up to 650 nm) photoluminescence of very narrow spectral widths. The roles of para-substituted anilines and their substituents in developing such energy levels are thoroughly studied by using transient absorption spectroscopy. We finally demonstrate light-emitting devices exploiting our C-dots as a phosphor, converting UV light to a variety of colors with internal quantum yields of ca. 20%.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, South Korea.
authors.forename: Woosung
authors.initials: W
authors.lastname: Kwon
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, South Korea.
authors.forename: Sungan
authors.initials: S
authors.lastname: Do
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), 2066 Seobu-ro, Jangan-gu, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Ji-Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 1] Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), 2066 Seobu-ro, Jangan-gu, Sungkyunkwan University, Suwon 440-746, South Korea [2] Department of Energy Science, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746, South Korea.
authors.forename: Mun
authors.initials: M
authors.lastname: Seok Jeong
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, South Korea.
authors.forename: Shi-Woo
authors.initials: SW
authors.lastname: Rhee