Tuning the Optical Properties of CsPbBr3 Nanocrystals by Anion Exchange Reactions with CsX Aqueous Solution

Abstract

Topotactic anion exchange has been developed to tune the composition and band gap energies of cesium lead halide (CsPbX3) perovskite nanocrystals (NCs). However, current anion exchange methods either require harsh conditions or take a long time to realize substantial substitution. Here, we present a method to modulate the composition of colloidal CsPbBr3 NCs through ultrasonication-assisted anion exchange with CsX (X = Cl, I) solution. Efficient anion exchange of CsPbBr3 NCs with Cl− or I− is realized with substitution ratio up to 93% and preservation of the pristine shape and structure of CsPbBr3 NCs. This anion exchange results in tunable emission, covering the whole visible spectral range, with relatively high photoluminescence quantum yield, narrow emission bandwidths, and good stability. This work provides a facile and efficient way to engineer the properties of halide perovskite NCs and has great potential for large-scale production of compositionally diverse perovskite NCs.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2592-4) contains supplementary material, which is available to authorized users.

Förster Resonance Energy Transfer Assisted Enhancement in Optoelectronic Properties of Metal Halide Perovskite Nanocrystals

“…As illustrated from the TEM and high-resolution TEM (HRTEM) images (Figure 2), the cubic-shaped CsPbBr 3 and CsPbCl 3 have lattice spacings of 6.09 and 5.91 Å (Figure 2a− d), respectively, and are in good agreement with earlier reports. 36,37 The profile plots along the four lines (1−4) in Figure S3 as drawn over a region are depicted in Figure S4. It is found that the atoms obtained in the HRTEM images are of different intensities.…”

All‐in‐One Process for Color Tuning and Patterning of Perovskite Quantum Dot Light‐Emitting Diodes

“…Cesium lead halide perovskite (CsPbX 3 , X = Cl, Br, and I) colloidal quantum dots (QDs), hereafter referred to as PeQD‐X, are considered promising materials for solar cells, [ 1 ] photodetectors, [ 2 ] and light‐emitting diodes (LEDs) [ 3 ] owing to their solution processability, narrow full width at half maximum (FWHM) of luminescence spectra, [ 4 ] and facile bandgap tunability. [ 5 ] Moreover, the all‐inorganic PeQD‐X is known to remain stable under ambient and high temperature conditions unlike hybrid methylammonium (MA)‐based MAPbX 3 materials. [ 6 ]…”

High‐Resolution Multicolor Patterning of Metal Halide Perovskite Nanocrystal Thin Films through Rapid‐Evaporation‐Assisted Strategy

“…We investigated the effective evaporation time of the droplet, which is in the range of the chemical reaction time of anion exchange and structural degradation time, to avoid the structural degradation of CPB PeNC thin films due to the polar solvent in the halide solution. [25][26][27] Structural, optical, and chemical analysis, as well as analytical estimation, show that anion exchange is successfully conducted without structural degradation when the droplet size is tens of microns or the evaporation time is less than the milli-second level. Taking advantage of our REA method, we successfully achieved multicolor patterns (418 to 688 nm) with high-resolution (diameter = 10.8 ± 1.2 µm and pitch = 1.2 ± 0.1 µm).…”