This project will integrate PbS quantum dots (QD) and photochromic organic linkers into photo-switchable macroscopic superstructures with long-range order. The photochromism is exploited to switch this coupled organic-inorganic nanostructure (COIN) between two distinct superstructural phases with large differences in the optical, electrical and structural properties. As such, the proposed materials constitute a bistable nanosystem to be switched between an “OFF” and an “ON” state by an external optical stimulus via the conformational change of the photochromic linker. This concept goes far beyond the previously demonstrated device applications of photochromic molecules in that their chemical coupling to the surface of QDs gives rise to entirely new physical properties. Examples include switchable fluorescence of the QDs, macroscopic structural and mechanical changes induced by light and optically controlled inter-nanoparticle electronic coupling. The potential of these properties for device applications will be explored.

July 2016 - December 2017

University of Tübingen
Intramural Funding Program for Young Investigators