title: Charging and Discharging Channels in Photoluminescence Intermittency of Single Colloidal CdSe/CdS Core/Shell Quantum Dot.
abstract: Understanding photoluminescence (PL) intermittency of single quantum dots (QDs) (intensity blinking by randomly switching between distinguishable brightness states under continuous excitation) has been a long-standing fundamental challenge and potential roadblock for their applications. Here we introduce a new analysis method for single-molecule spectroscopy that treats the blinking as photochemical/chemical processes (switching between neutral/bright and charged/dim states). It uncovers the channels for charging (bright to dim) and discharging (dim to bright) involved in PL blinking of single CdSe/CdS core/shell QDs. Both charging and discharging of the single CdSe/CdS core/shell QD possess a photochemical channel (∼10-5to 10-6events/photon) that linearly depends on excitation in both single- and multi-exciton regime. These two linear channels coupled to a spontaneous discharging channel (∼2 events/s) to dictate the QDs from nonblinking to gradually blinking under increasing excitation. For high-quality CdSe/CdS core/shell QDs, Auger ionization of multiexciton for both charging and discharging is negligible.
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Renyang
authors.initials: R
authors.lastname: Meng
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Qin
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.|State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Lin
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Hujia
authors.initials: H
authors.lastname: Cao
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Junliang
authors.initials: J
authors.lastname: Ma
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Wanzhen
authors.initials: W
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Tong
authors.affiliation: Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Xiaogang
authors.identifier: http://orcid.org/0000-0002-5606-8472
authors.initials: X
authors.lastname: Peng