As colloidal quantum dot (CQD) optoelectronic devices continue to improve, interest grows in the scaled-up and automated synthesis of high-quality materials. Unfortunately, all reports of record-performance CQD photovoltaics have been based on small-scale batch syntheses. Here we report a strategy for flow reactor synthesis of PbS CQDs and prove that it leads to solar cells having performance similar to that of comparable batch-synthesized nanoparticles. Specifically, we find that, only when using a dual-temperature-stage flow reactor synthesis reported herein, are the CQDs of sufficient quality to achieve high performance. We use a kinetic model to explain and optimize the nucleation and growth processes in the reactor. Compared to conventional single-stage flow-synthesized CQDs, we achieve superior quality nanocrystals via the optimized dual-stage reactor, with high photoluminescence quantum yield (50%) and narrow full width-half-maximum. The dual-stage flow reactor approach, with its versatility and rapid screening of multiple parameters, combined with its efficient materials utilization, offers an attractive path to automated synthesis of CQDs for photovoltaics and, more broadly, active optoelectronics. © 2013 American Chemical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-11-009-21, GRP-CF-2011-21-P/S
Acknowledgements: This publication is based in part on work supported by awards KUS-11-009-21 and GRP-CF-2011-21-P/S, made by King Abdullah University of Science and Technology (KAUST). V.M.B. acknowledges the support of the Oxford Martin School Fellowship and the Oxford Martin School. A.G. acknowledges the support of the Wolfson/Royal Society Merit Award, a Reintegration Grant under EC Framework VII, and the support of the EPSRC through Grant No. EP/I017070/1. We acknowledge the work of E. Palmiano, R. Wolowiec, and D. Kopilovic. We acknowledge the Canada Foundation for Innovation, project number 19119, the Ontario Research Fund of the Centre for Spectroscopic Investigation of Complex Organic Molecules and Polymers, and the Natural Sciences and Engineering Research Council (NSERC) of Canada for funding.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Materials Science(all)