Size control of CH3NH3PbBr3 perovskite cuboid fine crystals synthesized by ligand-free reprecipitation method

Cuboid fine crystals of methylammonium lead tribromide (MAPbBr3) perovskite have been synthesized by ligand-free reprecipitation method employing N,N-dimethylformamide (DMF) and 1,2,4-trichlorobenzene (TCB) as good and poor solvents, respectively. A small amount of DMF solution dissolving precursor chemicals of MAPbBr3 was rapidly injected to TCB under vigorous stirring to promote the reprecipitation. Mean crystal size could be varied between 70 and 600 nm by controlled addition of cyclohexane to TCB, since cyclohexane has been found to play a role to retard droplet diffusion. Cyclohexane was miscible with TCB but poorly miscible with DMF. Thus, addition of cyclohexane to TCB retarded diffusion of the injected droplets of DMF solution for reprecipitation of MAPbBr3. As the mixing of good and poor solvents was retarded, the recrystallization process was also slowed down, resulted in a small number of nuclei and their growth to large size. Moreover, extreme addition of cyclohexane has resulted in a hollow core spherical particles of MAPbBr3 due to aggregation of the cuboid fine crystals at the boundary between the added droplet and the poor solvent, so that the spheres formed preserving the shape of the droplet. Due to the limited miscibility of cyclohexane to DMF, increasing the cyclohexane content resulted in reduced rate of diffusion of the injected MAPbBr3 solution, thus increasing the size of the crystals.

Jaar van publicatie:2018

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:1

CSS-citation score:1

Auteurs:International

Authors from:Higher Education

Toegankelijkheid:Closed