One-Step Preparation of Cesium Lead Halide CsPbX₃ (X = Cl, Br, and I) Perovskite Nanocrystals by Microwave Irradiation

Abstract

CsPbX (X = Cl, Br, I) nanocrystals (NCs) are competitive emitting materials for illumination and display because of their outstanding photophysical properties. However, the conventional synthetic approaches suffer from low yields, complex procedures, and toxic chemicals. In this work, we demonstrate a one-step microwave-assisted approach to prepare CsPbX NCs. The homogeneous heating and rapid temperature increment of microwave preparation facilitate the growth of CsPbX NCs, producing the NCs with high photoluminescence quantum yields up to 90%, narrow emission full-width at half-maximum, and emission color tunable from blue to red. By optimizing the preparation conditions of the microwave-assisted approach, CsPbX NCs with cation- and halide anion-controlled emission properties, tunable reaction rate, and enhanced stability are prepared. Light-emitting diode (LED) prototypes are further fabricated by employing the as-prepared CsPbX NCs as the color conversion materials on commercially available 365 nm GaN LED chips.

Surface Halogen Compensation for Robust Performance Enhancements of CsPbX3 Perovskite Quantum Dots

“…In a mixed halide compounds QDs system, additional halogens increase the potential for the formation of V X defects, which represents difficulties for passivation. Therefore, the QYs of the CsPbBr 1.3 Cl 1.7 (≈460 nm) and CsPbBrI 2 (≈650 nm) are relatively low compared to those of the QDs with pure halide ions, especially for the blue CsPbBr 1.3 Cl 1.7 QDs, which have QYs lower than 40% …”

High-Detectivity Perovskite Light Detectors Printed in Air from Benign Solvents

“…Subsequently, they are deposited by a large-area bar-coating technique 29 and coated with a thin [6,6]-phenyl-C61-butyric acid methyl ester fullerene (PCBM) layer, which passivates surface traps, accepts electrons, and ensures selective charge circulation of holes. This strategy permits demonstration of the highest measured specific detectivity in printed light detectors to date, [14][15][16][17][18][30][31][32][33] reaching a maximum value of 7.23 3 10 13 cm Hz 0.5 /W in the visible spectrum, even higher than in commercially available Si photodiodes. Moreover, the gain and response time are at least one order of magnitude higher and lower, respectively, than in any other printed perovskite photodetector, which leads to a gain-bandwidth product of 7.5 3 10 6 Hz, thereby demonstrating a good balance between signal amplification and device response speed.…”

“…On top of that, the precursor-based approach restricts the available process window. [14][15][16][17][18] In fact, the final microstructure, which dominates the optoelectronic properties of the lightabsorbing layers, depends on how the constituent ions self-assemble during crystallization on the selected substrate, a complex function of precursor ratio, solvents, processing additives, substrate roughness and surface energy, atmospheric and environmental conditions, annealing temperature, and treatment time.…”

Highly Efficient and Stable Inorganic Perovskite Quantum Dots by Embedding into a Polymer Matrix

“…The all‐inorganic perovskite quantum dots (QDs) of the formula CsPbX 3 (X=Cl, Br, I) have specifically attracted considerable attention due to their narrow emission line width, size‐dependent luminescence behavior, covering the visible to near infrared range (400–800 nm), as well as superior photoluminescence quantum yield (PL QY) . These advantages make them the ideal candidates for light‐emitting diode (LED), lasers, solar cells, and photodetector .…”