Print Email Facebook Twitter Ga for Zn Cation Exchange Allows for Highly Luminescent and Photostable InZnP-Based Quantum Dots Title Ga for Zn Cation Exchange Allows for Highly Luminescent and Photostable InZnP-Based Quantum Dots Author Pietra, F. (TU Delft ChemE/Opto-electronic Materials) Kirkwood, N.R.M. (TU Delft ChemE/Opto-electronic Materials) De Trizio, L. (Istituto Italiano di Tecnologia) Hoekstra, Anne W. Kleibergen, Lennart Renaud, N. (TU Delft ChemE/Opto-electronic Materials) Koole, Rolf (Philips Lighting Research) Baesjou, Patrick J. (Philips Lighting Research; Universiteit Utrecht) Manna, L. (TU Delft QN/van der Zant Lab; Istituto Italiano di Tecnologia; Kavli institute of nanoscience Delft) Houtepen, A.J. (TU Delft ChemE/Opto-electronic Materials) Date 2017 Abstract In this work, we demonstrate that a preferential Ga-for-Zn cation exchange is responsible for the increase in photoluminescence that is observed when gallium oleate is added to InZnP alloy QDs. By exposing InZnP QDs with varying Zn/In ratios to gallium oleate and monitoring their optical properties, composition, and size, we conclude that Ga3+ preferentially replaces Zn2+, leading to the formation of InZnP/InGaP core/graded-shell QDs. This cation exchange reaction results in a large increase of the QD photoluminescence, but only for InZnP QDs with Zn/In ≥ 0.5. For InP QDs that do not contain zinc, Ga is most likely incorporated only on the quantum dot surface, and a PL enhancement is not observed. After further growth of a GaP shell and a lattice-matched ZnSeS outer shell, the cation-exchanged InZnP/InGaP QDs continue to exhibit superior PL QY (over 70%) and stability under long-term illumination (840 h, 5 weeks) compared to InZnP cores with the same shells. These results provide important mechanistic insights into recent improvements in InP-based QDs for luminescent applications. To reference this document use: http://resolver.tudelft.nl/uuid:6f9290e2-72f4-45c4-9387-7cf4995a2411 DOI https://doi.org/10.1021/acs.chemmater.7b00848 ISSN 0897-4756 Source Chemistry of Materials, 29 (12), 5192-5199 Part of collection Institutional Repository Document type journal article Rights © 2017 F. Pietra, N.R.M. Kirkwood, L. De Trizio, Anne W. Hoekstra, Lennart Kleibergen, N. Renaud, Rolf Koole, Patrick J. Baesjou, L. Manna, A.J. Houtepen Files PDF acs.chemmater.7b00848.pdf 2.44 MB Close viewer /islandora/object/uuid:6f9290e2-72f4-45c4-9387-7cf4995a2411/datastream/OBJ/view