(169b) High-Throughput Sonochemical Synthesis of Nanocrystals in Deep Eutectic Solvents

Semiconductor quantum dots (QD) have seen increasing interest in the past decade as these nanocrystals have tunable electronic/optical properties, while retaining structural stability. They have found application in catalysis, biomedicine, photovoltaic and light-emitting diodes (LED) technologies. One route for the synthesis of these materials is through the use of sonochemistry, in which an ultrasound wave is applied to a liquid sample containing dissolved nanocrystal precursors. An appealing choice for solvents are deep eutectic solvents (DESs): a class of materials with varied applications including catalysis, synthesis, extraction processes, drug solubilization and battery electrolytes. Their appeal for applications in nanocrystal synthesis stems from their high surface tension, which allows for aggressive cavitation, low vapor pressure, desirable for avoiding the formation of aerosol during the sonication step, and the tunability of their bulk properties. Additionally, it is also possible to embed the QD precursors in the solvent itself, as either a type I DES or a type III. A breadth of candidates with varying concentrations can be used to form DESs, leading to a vast design space. A liquid handling robot, a high-throughput sonication apparatus and a plate reader were used to test the formulation of different DES candidates and QD precursors. Through the use of high throughput experiments and data-driven design strategies we aimed to accelerate the optimization of materials based on their physicochemical and photoluminescence properties.