A CTAB-mediated antisolvent vapor route to shale-like Cs4PbBr6 microplates showing an eminent photoluminescence

A Universal Approach Toward Intrinsically Flexible All-Inorganic Perovskite-Gel Composites with Full-Color Luminescence

The combination of all-inorganic perovskites (PVSKs) and polymers allows for free-standing flexible optoelectronic devices. However, solubility difference of the PVSK precursors and concerns over the compatibility between polymer carriers and PVSKs imply a great challenge to incorporate different kinds of PVSKs into polymer matrices by the same manufacturing process. In this work, PVSK precursors are introduced into poly(2-hydroxyethyl acrylate) (PHEA) hydrogels in sequence, in which the PVSK-gel composites are achieved with full-color emissions by simply varying the precursor species. Moreover, it is found that CsBr has a higher interaction energy with the (111) plane of CsPbBr3 than the (110) plane; thus, the CsPbBr3 crystals with a shape of truncated cube and tetragon are observed during the CsPbBr3-Cs4PbBr6 phase transition over time. The PVSK-gel composites feature excellent bendability, elasticity, and stretchable deformation (tensile strain > 500%), which allows for 3D printing emissive customized stereoscopic architectures with shape-memory features.

Cesium Lead Bromide Perovskites: Synthesis, Stability, and Photoluminescence Quantum Yield Enhancement by Hexadecyltrimethylammonium Bromide Doping

Perovskite nanoparticles having a crystalline structure have attracted scientists' attention due to their great potential in optoelectronic and scintillation applications. The photoluminescence quantum yield (PLQY) is one of the main critical photophysical properties of the perovskite nanoparticles. Unfortunately, the main limitation of cesium lead halide perovskites is their instability in an ambient atmosphere, where they undergo a rapid chemical decomposition within time. For this purpose, hexadecyltrimethylammonium bromide (CTAB) was used as a surfactant dopant to test in the first place its effect on the stability of CsPbBr₃ perovskites and on the PLQY values of the prepared perovskites. The addition of CTAB has proven its efficiency in the formed CsPbBr₃ nanoparticles by increasing their thermal stability and by enhancing their PLQY up to 75%. These results were obtained after the successful preparation of CsPbBr₃ perovskite nanoparticles by optimizing three different reaction parameters, starting from the time of the reaction, moving to the concentration of lead bromide, and ending with the concentration of cesium oleate. Therefore, it was found that the most stable CsPbBr₃ perovskites were formed when mixing 0.15 g of lead bromide heated for 40 min with a volume of 1.2 mL of cesium oleate.