Photoinduced Anion Exchange in Cesium Lead Halide Perovskite Nanocrystals
- 16 March 2017
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 139 (12), 4358-4361
- https://doi.org/10.1021/jacs.7b01480
Abstract
Cesium lead halide (CsPbX3) perovskite nanocrystals (NCs) possess the unique capability of post-synthesis anion exchange providing facile tunability of the optical properties, which is usually achieved by mixing NCs with reactive anion precursors. In this work, we show that the controllable anion exchange can be achieved in a dihalomethane solution of CsPbX3 NC in the absence of any spontaneously reacting anion source using photoexcitation of CsPbX3 NCs as the triggering mechanism for the halide ion exchange. The reaction begins with the photoinduced electron transfer from CsPbX3 NCs to dihalomethane solvent molecules producing halide ions via reductive dissociation, which is followed by anion exchange. The reaction proceeds only in the presence of excitation light and the rate and extent of reaction can be controlled by varying the light intensity. Furthermore, the asymptotic extent of reaction under continuous excitation can be controlled by varying the wavelength of light that self-limits the reaction when light becomes off-resonance with the absorption of NCs. The light-controlled anion exchange demonstrated here can be utilized to pattern the post-synthesis chemical transformation of CsPbX3 NCs, not readily achievable using typical methods of anion exchange.Keywords
Funding Information
- Welch Foundation (A-1639)
- Division of Graduate Education (DGE-1252521)
This publication has 18 references indexed in Scilit:
- Tracking Iodide and Bromide Ion Segregation in Mixed Halide Lead Perovskites during PhotoirradiationACS Energy Letters, 2016
- Synthesis of Composition Tunable and Highly Luminescent Cesium Lead Halide Nanowires through Anion-Exchange ReactionsJournal of the American Chemical Society, 2016
- Solution Synthesis Approach to Colloidal Cesium Lead Halide Perovskite Nanoplatelets with Monolayer-Level Thickness ControlJournal of the American Chemical Society, 2016
- Highly Luminescent Colloidal Nanoplates of Perovskite Cesium Lead Halide and Their Oriented AssembliesJournal of the American Chemical Society, 2015
- Tuning the Optical Properties of Cesium Lead Halide Perovskite Nanocrystals by Anion Exchange ReactionsJournal of the American Chemical Society, 2015
- Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I)Nano Letters, 2015
- Ionic transport in hybrid lead iodide perovskite solar cellsNature Communications, 2015
- Defect migration in methylammonium lead iodide and its role in perovskite solar cell operationEnergy & Environmental Science, 2015
- Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color GamutNano Letters, 2015
- Reversible photo-induced trap formation in mixed-halide hybrid perovskites for photovoltaicsChemical Science, 2014