Oscillatory Microprocessor for Growth and in Situ Characterization of Semiconductor Nanocrystals

摘要

An automated two-phase small scale platform based on controlled oscillatory motion of a droplet within a 12 cm long tubular Teflon reactor is designed and developed for high-throughput in situ studies of a solution-phase preparation of semiconductor nanocrystals. The unique oscillatory motion of the droplet within the heated region of the reactor enables temporal single-point spectral characterization of the same nanocrystals with a time resolution of 3 s over the course of the synthesis time without sampling while removing the residence time limitation associated with continuous flow-based strategies. The developed oscillatory microprocessor allows for direct comparison of the high temperature and room temperature spectral characteristics of nanocrystals. Utilizing this automated experimental strategy, we study the effect of temperature on the nucleation and growth of II-VI and III-V semiconductor nanocrystals. The automated droplet preparation and injection of the precursors combined with the oscillatory flow technique allows 7500 spectral data within a parameter space of 10 min reaction time at ten different temperatures and five different precursor ratios to be obtained automatically using only 250 mu L of each precursor solution. The oscillatory microprocessor platform provides real-time in situ spectral information at the synthesis temperature, vital for fundamental studies of different mechanisms involved during the nucleation and growth stages of different types of nanomaterials.