TY - JOUR
T1 - Amine-Free Synthesis of Cesium Lead Halide Perovskite Quantum Dots for Efficient Light-Emitting Diodes
AU - Yassitepe, Emre
AU - Yang, Zhenyu
AU - Voznyy, Oleksandr
AU - Kim, Younghoon
AU - Walters, Grant
AU - Castañeda, Juan Andres
AU - Kanjanaboos, Pongsakorn
AU - Yuan, Mingjian
AU - Gong, Xiwen
AU - Fan, Fengjia
AU - Pan, Jun
AU - Hoogland, Sjoerd
AU - Comin, Riccardo
AU - Bakr, Osman M.
AU - Padilha, Lazaro A.
AU - Nogueira, Ana F.
AU - Sargent, Edward H.
N1 - Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2016/12/20
Y1 - 2016/12/20
N2 - Cesium 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.
AB - Cesium 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.
KW - perovskite quantum dots
KW - quantum dot LEDs
KW - quarternary alkylammonium halides
KW - transient absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84995977443&partnerID=8YFLogxK
U2 - 10.1002/adfm.201604580
DO - 10.1002/adfm.201604580
M3 - Article
AN - SCOPUS:84995977443
SN - 1616-301X
VL - 26
SP - 8757
EP - 8763
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 47
ER -
