title: Single-particle spectroscopic measurements of fluorescent graphene quantum dots.
abstract: We have performed the first single-particle spectroscopic measurements on individual graphene quantum dots (GQDs) and revealed several intriguing fluorescent phenomena that are otherwise hidden in the optical studies of ensemble GQDs. First, despite noticeable differences in the size and the number of layers from particle to particle, all of the GQDs studied possess almost the same spectral lineshapes and peak positions. Second, GQDs with more layers are normally brighter emitters but are associated with shorter fluorescent lifetimes. Third, the fluorescent spectrum of GQDs was red-shifted upon being aged in air, possibly due to the water desorption effect. Finally, the missing emission of single photons and stable fluorescence without any intermittent behavior were observed from individual GQDs.
authors.affiliation: National Laboratory of Solid State Microstructures and School of Physics, Nanjing University , Nanjing 210093, China.
authors.forename: Qinfeng
authors.initials: Q
authors.lastname: Xu
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hua
authors.forename: Qi
authors.initials: Q
authors.lastname: Xue
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhang
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wang
authors.forename: Dengyu
authors.initials: D
authors.lastname: Pan
authors.forename: Min
authors.initials: M
authors.lastname: Xiao
mesh_terms: D000388:Air; D019187:Cadmium Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D049449:Luminescence; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D010777:Photochemistry; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D012666:Semiconductors; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013499:Surface Properties; D013696:Temperature; D014867:Water
chemical_list: D019187:Cadmium Compounds; D004396:Coloring Agents; D018036:Selenium Compounds; D014867:Water; D006108:Graphite; C058667:cadmium selenide