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

Abstract

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 CsPbBr 3 perovskites and on the PLQY values of the prepared perovskites. The addition of CTAB has proven its efficiency in the formed CsPbBr 3 nanoparticles by increasing their thermal stability and by enhancing their PLQY up to 75%. These results were obtained after the successful preparation of CsPbBr 3 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 CsPbBr 3 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.

Probing the Structural Degradation of CsPbBr3 Perovskite Nanocrystals in the Presence of H2O and H2S: How Weak Interactions and HSAB Matter

“…The search for new materials for efficient and cost-effective harvesting of light energy has been hovering around lead halide perovskites for the past decade, owing to their high extinction coefficient, absorption in a broad wavelength range, and large exciton diffusion lengths. − More interestingly, the emission of lead halide perovskites can be tuned in the entire visible region, by postsynthetic anion exchange reaction, in an easier manner. − The emission quantum yield of the lead halide perovskites is close to unity and also shows an exceptional electroluminescent yield with a fairly narrow emission profile. − Thus, lead halide perovskites are proposed as an alternate material for the fabrication of light-emitting diodes (LED), display devices, and sensors. ,− Apart from this, lead halide perovskite is the one of the materials that showed a commendable efficiency for solar cells, so far, in the laboratory. − Many of the interesting properties of lead halide perovskites are attributed to their peculiar crystal structure. − Even though lead halide perovskite proved its efficiency for various applications, the stability under ambient conditions is a major concern. − Lead halide perovskites are known to decompose in the presence of small molecules like water . Water is also known to be used as a greener solvent for the synthesis of lead halide perovskites at moderately high temperatures. , In order to improve the stability of lead halide perovskites under ambient conditions, especially in humid atmospheres, the exact mechanism of moisture-assisted decomposition needs to be understood.…”

Highly Stable and Biocompatible CsPbBr3 Nanocrystals Synthesized by Different Methods for Bioimaging Applications

“…All inorganic halogen perovskite nanocrystals (PNCs) have shown great potential in the field of fluorescent materials and have garnered significant attention from researchers. − Among them, CsPbBr 3 PNCs have emerged as promising candidates for biological imaging and fluorescent probes due to their excellent luminescence properties, such as high photoluminescence quantum yield (PLQY), narrow luminescence spectrum, fast response speed, and lower fluorescence scintillation. − However, CsPbBr 3 PNCs suffer from several notable defects, including poor stability, hydrolysis in humid conditions, and the tendency to lose Pb 2+ , leading to serious cytotoxicity. − Therefore, it is essential to find a suitable method to enhance the stability of CsPbBr 3 PNCs and reduce toxicity, particularly for their application in demanding biomedical environments.…”