TY - JOUR
T1 - Exploring the Role of Surface States in Emissive Carbon Nanodots
T2 - Analysis at Single-Particle Level
AU - Kim, Dongseok
AU - Calabro, Rosemary L.
AU - Masud, Abdullah A.
AU - Kothalawala, Nadeesha L.
AU - Gu, Minsu
AU - Kwak, Seung Yeon
AU - Son, Won Joon
AU - Hwang, Kyu Young
AU - Choi, Hyeonho
AU - Richards, Christopher I.
AU - Kim, Doo Young
AU - Kim, Byeong Su
N1 - Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/12/13
Y1 - 2021/12/13
N2 - Fluorescent carbon nanodots (CDs) have been highlighted as promising semiconducting materials due to their outstanding chemical and optical properties. However, the intrinsic heterogeneity of CDs has impeded a clear understanding of the mechanisms behind their photophysical properties. In this study, as-prepared CDs are fractionated via chromatography to reduce their structural and chemical heterogeneity and analyzed through ensemble and single-particle spectroscopies. Many single particles reveal fluorescence intensity fluctuations between two or more discrete levels with bi-exponential decays. While the intrinsic τ1 components are uniform among single particles, the τ2 components from molecule-like emissions spans a wider range of lifetimes, reflecting the inhomogeneity of the surface states. Furthermore, it is concluded that the relative population and chemical states of surface functional groups in CDs have a significant impact on emissive states, brightness, blinking, stability, and lifetime distribution of photoluminescence.
AB - Fluorescent carbon nanodots (CDs) have been highlighted as promising semiconducting materials due to their outstanding chemical and optical properties. However, the intrinsic heterogeneity of CDs has impeded a clear understanding of the mechanisms behind their photophysical properties. In this study, as-prepared CDs are fractionated via chromatography to reduce their structural and chemical heterogeneity and analyzed through ensemble and single-particle spectroscopies. Many single particles reveal fluorescence intensity fluctuations between two or more discrete levels with bi-exponential decays. While the intrinsic τ1 components are uniform among single particles, the τ2 components from molecule-like emissions spans a wider range of lifetimes, reflecting the inhomogeneity of the surface states. Furthermore, it is concluded that the relative population and chemical states of surface functional groups in CDs have a significant impact on emissive states, brightness, blinking, stability, and lifetime distribution of photoluminescence.
KW - Carbon nanodots
KW - Column chromatography
KW - Photoluminescence
KW - Single-particle spectroscopy
KW - Surface functional groups
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U2 - 10.1002/asia.202101087
DO - 10.1002/asia.202101087
M3 - Article
C2 - 34734682
AN - SCOPUS:85119327075
SN - 1861-4728
VL - 16
SP - 4155
EP - 4164
JO - Chemistry - An Asian Journal
JF - Chemistry - An Asian Journal
IS - 24
ER -