The off‐stoichiometry effects and gram‐scale production of luminescent CuInS2‐based semiconductor nanocrystals, as well as their application in electroluminescence devices are reported. The crystal structures and optical properties of CuInS2 nanocrystals can be significantly influenced by controlling their [Cu]/[In] molar ratio. A simple model adapted from the bulk materials is proposed to explain their off‐stoichiometry effects. Highly emissive and color‐tunable CuInS2‐based NCs are prepared by a combination of [Cu]/[In] molar ratio optimization, ZnS shell coating, and CuInS2–ZnS alloying. The method is simple, hassle‐free, and easily scalable to fabricate tens of grams of nanocrystal powders with photoluminescence quantum yields up to around 65%. Furthermore, the performance of high‐quality CuInS2‐based NCs in electroluminescence devices is examined. These devices have lower turn‐on voltages of around 5 V, brighter luminance up to approximately 2100 cd m−2 and improved injection efficiency of around 0.3 lm W−1 (at 100 cd m−2) in comparison to recent reports.

No abstract

A novel giant surfactant possessing a well-defined hydrophilic head and a hydrophobic polymeric tail, polystyrene-(carboxylic acid-functionalized polyhedral oligomeric silsesquioxane) conjugate (PS-APOSS), has been designed and synthesized via living anionic polymerization, hydrosilylation, and thiol-ene "click" chemistry. PS-APOSS forms micelles in selective solvents, and the micellar morphology can be tuned from vesicles to wormlike cylinders and further to spheres by increasing the degree of ionization of the carboxylic acid. The effect of APOSS-APOSS interactions was proven to be essential in the morphological transformation of the micelles. The PS tails in these micellar cores were found to be highly stretched in comparison with those in traditional amphiphilic block copolymers, and this can be explained in terms of minimization of free energy. This novel class of giant surfactants expands the scope of macromolecular amphiphiles and provides a platform for the study of the basic physical principles of their self-assembly behavior.

No abstract