Textured MAPbI ₃ Thin Films Achieved via Solvent Engineering in the Solution‐Shearing Process

Solvent mixtures for making uniform, crystalline methylammonium lead iodide (MAPbI(3)) perovskite films are provided. The solvents dimethyl sulfoxide (DMSO), & gamma;-butyrolactone (GBL), and 1-methyl-2-pyrrolidinone (NMP) are examined as well as their binary combinations to prepare solution-sheared perovskite films at higher than 150 & DEG;C temperatures. Characterization methods such as imaging, X-ray diffraction, grazing-incidence wide-angle X-ray scattering, and photoluminescence (PL) to evaluate the crystal size, quality, and ordering that determine the viability of these films for device applications are explored and then a perovskite solar cell is made to test the stability of the most promising film. Excellent macroscopic crystals, over 1 mm in length, are achieved using a solvent mixture containing equal volumes of DMSO and NMP. These superior 3D MAPbI(3) films, which retain solvent-perovskite intermediate phases and exhibit high crystalline ordering, are essential for high-performing and stable optoelectronic devices.