Millimeter-Size All-inorganic Perovskite Crystalline Thin Film Grown by Chemical Vapor Deposition

The chemical vapor deposition (CVD) method is a dry approach that can produce high quality crystals and thin films at large scale which can be easily adapted by industry. In this work, CVD technology is employed to grow high quality, large size all-inorganic cesium lead bromide perovskite crystalline film for the first time. The obtained films have millimeter size crystalline domains with high phase purity. The growth kinetics are examined in detail by optical microscopy and X-ray diffraction. The deposition rate and growth temperature are found to be the key parameters allowing to achieve large scale crystal growth. The large crystalline grains exhibit exceptional optical properties including negligible Stokes shift and uniform photoluminescence over a large scale. This suggests a high degree of crystallinity free from internal strain or defects. A lateral diode within one large crystalline grain is further fabricated and significant photo-generated voltage and short circuit current are observed, suggesting highly efficient carrier transport and collections without scattering within the grain. This demonstration suggests that the CVD grown all-inorganic perovskite thin films enable a promising fabrication route suitable for photovoltaic or photo-detector applications.