High‐Throughput Robotic Synthesis and Photoluminescence Characterization of Aqueous Multinary Copper–Silver Indium Chalcogenide Quantum Dots
Oleksandr Stroyuk, Oleksandra Raievska, Stefan Langner, Christian Kupfer, Anastasia Barabash, Dmytro Solonenko, Yu. M. Azhniuk, Jens Hauch, Andres Osvet, Miroslaw Batentschuk, Dietrich R. T. Zahn, Christoph J. Brabec
Abstract
Abstract The feasibility of a high‐throughput robot‐assisted synthesis of complex Cu 1‐ x Ag x InS y Se 1‐ x (CAISSe) quantum dots (QDs) by spontaneous alloying of aqueous glutathione‐capped Ag–In–S, Cu–In–S, Ag–In–Se, and Cu–In–Se QDs is demonstrated. Both colloidal and thin‐film core CAISSe and core/shell CAISSe/ZnS QDs are produced and studied by high‐throughput semiautomated photoluminescence (PL) spectroscopy. The silver‐copper‐mixed QDs reveal clear evidence of a band bowing effect in the PL spectra and higher average PL lifetimes compared to the counterparts containing silver or copper only. The photophysical analysis of CAISSe and CAISSe/ZnS QDs indicates a composition‐dependent character of the nonradiative recombination in QDs. The rate of this process is found to be lower for mixed copper‐silver‐based QDs compared to Cu‐ or Ag‐only QDs. The combination of the band bowing effect and the suppressed nonradiative recombination of CAISSe QDs is beneficial for their applications in photovoltaics and photochemistry. The synergy of high‐throughput robotic synthesis and a high‐throughput characterization in this study is expected to grow into a self‐learning synthetic platform for the production of metal chalcogenide QDs for light‐harvesting, light‐sensing, and light‐emitting applications.