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.