Amine-Free Synthesis of Cesium Lead Halide Perovskite Quantum Dots for Efficient Light-Emitting Diodes
Castañeda, Juan Andres
Padilha, Lazaro A.
Nogueira, Ana F.
Sargent, Edward H.
KAUST DepartmentKAUST Solar Center (KSC)
Physical Sciences and Engineering (PSE) Division
KAUST Catalysis Center (KCC)
KAUST Grant NumberKUS-11-009-21
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AbstractCesium lead halide perovskite quantum dots (PQDs) have attracted significant interest for optoelectronic applications in view of their high brightness and narrow emission linewidth at visible wavelengths. A remaining challenge is the degradation of PQDs during purification from the synthesis solution. This is attributed to proton transfer between oleic acid and oleylamine surface capping agents that leads to facile ligand loss. Here, a new synthetic method is reported that enhances the colloidal stability of PQDs by capping them solely using oleic acid (OA). Quaternary alkylammonium halides are used as precursors, eliminating the need for oleylamine. This strategy enhances the colloidal stability of OA capped PQDs during purification, allowing us to remove excess organic content in thin films. Inverted red, green, and blue PQD light-emitting diodes (LED) are fabricated for the first time with solution-processed polymer-based hole transport layers due to higher robustness of OA capped PQDs to solution processing. The blue and green LEDs exhibit threefold and tenfold improved external quantum efficiency (EQE), respectively, compared to prior related reports for amine/ammonium capped cross-linked PQDs. The brightest blue LED based on all inorganic CsPb(Br1- xClx)3 PQDs is also reported. Â© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
CitationYassitepe E, Yang Z, Voznyy O, Kim Y, Walters G, et al. (2016) Amine-Free Synthesis of Cesium Lead Halide Perovskite Quantum Dots for Efficient Light-Emitting Diodes. Advanced Functional Materials 26: 8757–8763. Available: http://dx.doi.org/10.1002/adfm.201604580.
SponsorsE.Y., Z.Y., and O.V. contributed equally to this work. This publication was based in part on work supported by the Award KUS-11-009-21, made by the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund – Research Excellence Program, and by the Natural Sciences and Engineering Research Council of Canada (NSERC). E.Y. acknowledges support from FAPESP-BEPE (2014/18327-9) and FAPESP (2013/05798-0) fellowships. E.Y. acknowledges LNnano-CNPEM (TEM-19813) for high resolution TEM facility. J.A.C. and L.A.P. acknowledge the financial support from FAPESP (Project number 2013/16911-2). A.F.N. acknowledges FAPESP, CNPq, and INEO. The authors thank Dr. Y. Zhao for useful discussions. The authors thank L. Levina, E. Palmiano, R. Wolowiec, and D. Kopilovic for their technical help over the course of this study.
JournalAdvanced Functional Materials