Parametric dependence of CsPbI2Br perovskite film growth using a mist chemical vapor deposition method

Using an atmospheric mist chemical vapor deposition, we successfully fabricated inorganic CsPbI2Br films under various growth conditions. The process condition of the film growth was experimentally determined as follows: 0.4 M CsPbI2Br precursor in a mixed solvent with a 4:1 ratio (v/v %) of N, N-dimethylformamide and dimethyl sulfoxide, carrier and dilution N-2 flow rates of 200 and 1500 cc/min, substrate temperature of 68 degrees C, and growth time of 35 min. In the characterization of the structural and optical properties, all the films exhibited a welldefined alpha-CsPbI2Br cubic crystal structure and optical bandgap energy of 1.914 eV. For the preparation of smooth defect-free CsPbI2Br films, it is crucial to maintain a growth condition with a narrow operation tolerance to stabilize the amount of precursor mist that flows through a rectangular channel reactor with a proper ratio of similar to 1/10 for the carrier-to-dilution N-2 gas flow rate at the low substrate temperature of 68 degrees C.