title: Study on the photoluminescence character of water-soluble CdSe nanocrystals under ambient conditions.
abstract: Water soluble, thioglycolic acid (TGA) modified CdSe nanocrystals (NCs) have been prepared in aqueous media by the reaction between Cd2+ and NaHSe. Although initially these quantum dots (QDs) display photoluminescence (PL) with very low quantum yields (QY), upon prolonged exposure to ambient light, a strong PL enhancement by illumination is observed which leads to water soluble QDs with high luminescence. This result may have important application potential in biological or other fields. The primary reason for the luminescence enhancement is concluded to be the incorporation of sulfide ions from TGA into the lattice of CdSe NCs and the subsequent formation of alloy structures. Moreover, the CdSe/CdS core-shell structured QDs synthesized in aqueous solutions also consolidate this conclusion.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xue
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhang
authors.forename: Linhai
authors.initials: L
authors.lastname: Zhuo
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D018036:Selenium Compounds / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D046911:Macromolecular Substances; D018036:Selenium Compounds; D014867:Water; C058667:cadmium selenide