Morphologically Controlled Synthesis of Cs2SnCl6 Perovskite Crystals and Their Photoluminescence Activity

The Cs 2SnX 6 perovskites have attracted much attention due to excellent optoelectronic properties and high stability. In the present work, we have focused on the morphology control and photoluminescence characteristics of the Cs 2SnCl 6 perovskite crystals. The synthesis process of the Cs 2SnCl 6 crystals includes two stages composed of the formation of initial crystals and the growth of Cs 2SnCl 6; the later originated from the oxidization of CsSnCl 3. This process has been confirmed by Scanning electron microscope (SEM) and X-rays diffraction (XRD). By controlling the concentration of the initial reactants and hydrochloric acid in the solution to change the supersaturation of the solution, different crystal morphologies, such as truncated octahedron, octahedron, hexapod, quasi-sphere, have been obtained. In relatively a low supersaturation solution, the amount of growth units dominates the crystal growth process to obtain the hexapod and self-assembly crystals. In contrast, in relatively high supersaturation solution, nucleation predominates to yield small size truncated octahedrons and near-spherical Cs 2SnCl 6 crystals. The synthesized Cs 2SnCl 6 crystals have shown a wide emission band peaking at 450 nm with full width at half maximum (FWHM) 63 nm due to the defects introduced by Sn 2+. The photoluminescence intensities of crystals synthesized at various conditions exhibited considerable difference, which was about 60 times between the highest and the lowest. View Full-Tex