Gold-tipped CdSe/CdZnS colloidal quantum wells as non-quenching plasmonic particles for optical applications

Abstract

Here, a new one-pot and heterogeneous synthesis method for AuNP-tipped CdSe/CdZnS colloidal quantum wells (CQWs) as non-quenching plasmonic particles is reported. We propose and demonstrate the synthesis and characterization of such plasmonic particles that prevent the quenching of photoluminescence of the emitters. A synthesis of the gold-tipped CQWs in a heterogeneous phase was performed without gold organosol preparation. The size of gold nanoparticles attached to the CdSe/CdZnS CQWs was controlled by reaction time and the addition of octanethiol ligand, which has a tendency to bind gold nanoparticles. Absorption and photoluminescence spectra of the CQWs after the addition of progressively higher amounts of AuNP-tipped CdSe/CdZnS CQWs into solutions proved their usability as non-quenching plasmonic particles. These highly photoluminescent CQWs retain their photostability for more than 6 months when they are mixed with AuNP-tipped CQWs in organic solvents. Besides, AuNP-tipped CdSe/CdZnS CQWs dopped polystyrene films were prepared to observe temperature increase under near-infrared (NIR) excitation. The temperature increase from 25.6 °C to 38.0 °C caused by the plasmonic effect of AuNPs in the composite films was measured by exciting the films with an 808 nm laser. These easy-to-produce plasmonic particles offer new opportunities for the simple implementation of high-performance optical resonators for colloidal lasers.