Higher stability and better photoluminescence quantum yield of cesium lead iodide perovskites nanoparticles in the presence of CTAB ligand.

Inorganic halide perovskites, such as CsPbI3, have unique optoelectronic properties which made them promising candidates for several applications. Unfortunately, these perovskites undergo rapid chemical decomposition and transformation into yellow δ-phase. Thus, the synthesis of stable cesium lead iodide perovskites remains an actual challenging field and it is imperative to develop a stabilized black phase for photovoltaic applications. For this purpose, a surfactant ligand was used to control the synthesis of inorganic perovskite CsPbI3 nanoparticles. Herein we demonstrate a new avenue for lead halide perovskites with the addition of either hexadecyltrimethylammonium bromide (CTAB) or silica nanoparticles to maintain in the first place; the stability of the α-CsPbI3 phase, and later on to boost their photoluminescence quantum yield (PLQY). The prepared perovskites were characterized using UV-visible absorption spectroscopy, fluorescence spectroscopy, scanning electron microscopy, thermogravimetric analysis and X-Ray diffraction technique. Results show higher stability of α-CsPbI3 phase and improvement in PLQY % to reach 99% enhancement in presence of CTAB. Moreover, the photoluminescence intensity of CsPbI3 nanoparticles was higher and was maintained for a longer duration in the presence of CTAB.