title: Experimental and theoretical investigations of the ligand structure of water-soluble CdTe nanocrystals.
abstract: The unique optical properties, such as size-tunable absorption and emission, caused semiconductor nanocrystals to attract a great deal of interest for recent technological developments. For the evaluation of semiconductor nanocrystals as new materials for various applications like optoelectronic devices, knowledge of the structure-property relationships is indispensable, but still presents a challenge. Here, we address these challenges for thioglycolic acid-capped CdTe nanocrystals with a focus on the quantification of thiol ligands, identification of the ligand shell structure and their influence on the optical properties of these nanocrystals. We present the use of a simple analytical technique, the Ellman's test, and ICP-OES analysis for the study of the surface chemistry of these nanomaterials. Together with theoretical calculations, the results of these studies show the strong influence of the amount of Cd-thiolates present in the ligand shell on the concentration-dependent emission properties, thereby providing the basis for a better understanding of the chemical nature of the NC-ligand interface. In this context, the present work contributes to the establishment of a clearer picture and better control of the surface chemistry, which will provide the basis for the design of highly emitting nanocrystals and the prediction of their applicability.
authors.affiliation: Physical Chemistry and Center for Advancing Electronics Dresden, TU Dresden, Bergstr. 66b, 01062 Dresden, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Leubner
authors.forename: Soheil
authors.initials: S
authors.lastname: Hatami
authors.forename: Nehir
authors.initials: N
authors.lastname: Esendemir
authors.forename: Tommy
authors.initials: T
authors.lastname: Lorenz
authors.forename: Jan-Ole
authors.initials: JO
authors.lastname: Joswig
authors.forename: Vladimir
authors.initials: V
authors.lastname: Lesnyak
authors.forename: Sebastian
authors.initials: S
authors.lastname: Recknagel
authors.forename: Nikolai
authors.initials: N
authors.lastname: Gaponik
authors.forename: Ute
authors.initials: U
authors.lastname: Resch-Genger
authors.forename: Alexander
authors.initials: A
authors.lastname: Eychmüller