Aqueous Synthesis of Lead Halide Perovskite Nanocrystals with High Water Stability and Bright Photoluminescence

Abstract

Lead halide perovskite nanocrystals (NCs) have attracted intense attention because of their excellent optoelectronic properties. The ionic nature of halide perovskites makes them highly vulnerable to water. Encapsulation of perovskite NCs with inorganic or organic materials has been reported to enhance their stability; however, they often suffer from large aggregation size, low water solubility, and difficulty for further surface functionalization. Here, we report a facile aqueous process to synthesize water-soluble CsPbBr 3 /Cs 4 PbBr 6 NCs with the assistance of a fluorocarbon agent (FCA), which features a novel mechanism of the perovskite crystallization at the oil/water interface and direct perovskite NCs/FCA self-assembly in an aqueous environment. The products exhibit a high absolute photoluminescence quantum yield (PLQY) of ∼80% in water with the PL lasting for weeks. Through successive ionic layer adsorption and reaction, BaSO 4 was further applied to encapsulate the NCs, which greatly enhanced their stability in phosphate-buffered saline solutions. The high stability in water and saline solution, high PLQY, and tunable emission wavelength, together with the successful demonstration of brain tissue labeling and PL under X-ray excitation, make our perovskite NCs a promising choice for X-ray fluorescent biolabels.

Transient Resistive Switching for Nonvolatile Memory Based on Water‐Soluble Cs4PbBr6 Perovskite Films

“…It is noted that the films quickly dissolved after immersed in DI water. Finally, the last SEM image shows that the Cs 4 PbBr 6 films have been completely dissolved after 2 s. The aforementioned shorter dissolution time and good retention performances of Cs 4 PbBr 6 films can be attributed to small thickness and higher sensitivity toward DI water than the reported of CsPbBr 3 material …”

“…Figure 5a shows the www.advancedsciencenews.com www.pss-rapid.com and good retention performances of Cs 4 PbBr 6 films can be attributed to small thickness and higher sensitivity toward DI water than the reported of CsPbBr 3 material. [2,33,34] Therefore, it suggests that the devices utilizing all-inorganic perovskite-based Cs 4 PbBr 6 materials are transient, which is potentially suitable for short period data storage units as well as implantable electronics with human body or environmental sensors. Simultaneously, if the suitable electrode materials such as dissolvable metals (e.g., Mg, Zn, or Mo) are selected, the entire electronic unit can be degraded in DI water to obtain a fully selfdestructive transient electronic device.…”

Synthesis of water-dispersible, plate-like perovskites and their core–shell nanocrystals

“…So far, few syntheses of water-dispersible perovskites have been reported due to the limited number of available watersoluble dispersants that can stabilise (RNH 3 ) m MX n structures. 34,35 Furthermore, water-dispersibility is absolutely essential for preparing core-shell structures because the shell is generally produced in the water phase. Actually, an experimental attempt to prepare a metal-shell covering on waterinsoluble (CH 3 NH 3 ) 2 PdCl 4 nanocrystals failed (Fig.…”

Stable Perovskite Quantum Dots Coated with Superhydrophobic Organosilica Shells for White Light‐Emitting Diodes

“…[15,17] However,p erovskite QDs suffer from poor stability against environmental factors, such as light, oxygen,heat, etc., [15] especially,p olar solvents or moisture due to their inherent ionic nature and low formation energy, [18][19][20] which seriously impedes their practical applications.T ow ork out these issues, al ot of methods have been developedi nr ecent years. [15][16][17][21][22][23][24] For ex-ample,o rganic ligands passivated perovskite QDs performed increasing tolerance to humidity because the hydrophobic alkyl chains could prevent the surfaced efects from humidity. [23] X-ray lithography on perovskite QDs could enhancet he stability by generating intermolecular C=Cb ondinga mong organic ligands.…”

“…The PL emissions of MAPbBr 3 QDs/FSiO 2 have as lightb lueshift (Figure4b) which maybe attributed to the electric interaction among CÀFb onds and Br À in perovskite crystalsw hen temperature increases. [24] Furthermore,w ef abricated white LED (WLED) by mixing green MAPbBr 3 QDs/FSiO 2 and red MAPbI 3 QDs/FSiO 2 powders with silicon resin thoroughly,a nd then coating on a4 50 nm blue chip. The obtained WLED is shining bright white light as shown in the inset of Figure4c.…”