Brightly Luminescent Core/Shell Nanoplatelets with Continuously Tunable Optical Properties
Abstract
A straightforward, rapid method to create colloidally stable and brightly luminescent core/shell CdSe‐based nanoplatelets (NPLs) with fluorescence quantum yields (QYs) up to 50% is demonstrated. A layer‐by‐layer deposition technique is used which is based on a two‐phase mixture—consisting of a nonpolar phase, which includes the NPLs, and a saturated ionic polar phase—to separate the reagents and hinder the nucleation of the shell material. The deposition of the first sulfur layer leads to a significant redshift (by more than 100 nm) of the optical absorption and emission of the NPLs. Hence, by varying either the sulfur precursor content or the reaction time, one can precisely and continuously tune the absorption and emission maxima from 520 to 630 nm. This evolution of the absorption onset during the shell growth is explained quantitatively using density‐functional theory and atomistic statistical simulations. The emission can be further enhanced by exposure of the NPL solution to ambient sunlight. Finally, it is demonstrated that the core/shell NPLs can be transferred from the organic solution to aqueous media with no reduction of their QY, which opens the door to a broad range of practical applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 24, 2019
- Source ID
- 10.1002/adom.201801478
Entities
People
- Alexander Eychmüller
- Christian Meerbach
- Dietrich R. T. Zahn
- Kristian Schneider
- Oleksandr Selyshchev
- Remo Tietze
- Sascha Voigt
- Steven C Erwin
- Vladimir Lesnyak
- Vladimir Sayevich
- Volodymyr M. Dzhagan
- Zhiya Dang
Organizations
- Chemnitz University of Technology
- European Research Council
- German Academic Exchange Service
- Institute of Semiconductor Physics
- Istituto Italiano di Tecnologia
- Office of Naval Research
- Technische Universität Dresden
- United States Naval Research Laboratory
- Volkswagen Foundation