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

Abstract

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.

Solvent Recrystallization‐Enabled Green Amplified Spontaneous Emissions with an Ultra‐Low Threshold from Pinhole‐Free Perovskite Films

“…However, the PL peak shifted from ≈520 to ≈518 nm, corresponding to a reduced Stokes shift from 46.8 to 37.6 meV, which indicates an enlarged grain size and improved crystallinity and is in agreement with the XRD spectra analysis. [ 30 ] The rise in full width at half maximum (FWHM) from 16.8 to 20.9 nm may be attributed to the increase of inhomogeneous size distribution as well as the density of states near the band edge. [ 31 ] The time‐resolved PL (TRPL) spectra of these films contain single exponential decay curves at low pump densities (<50 nJ cm −2 ) with time constants of 1.6 and 2.0 ns (Figure S3a, Supporting Information).…”

Film Fabrication of Perovskites and their Derivatives for Photovoltaic Applications via Chemical Vapor Deposition

“…Interestingly, thin films of lead-free materials were also successfully deposited via one-step CVD at ambient atmosphere or controlled pressure. , The novelty in the deposition process of MA 3 Bi 2 I 9 is the showerhead-based deposition tool for perovskites, which offered precise control options and paved the way for large-area production (Figure b) . Recently, it was first demonstrated that one-step CVD could also be utilized to deposit millimeter-size CsPbBr 3 crystalline thin films with high phase purity, showing a promising preparation method suitable for PV applications (Figure c, d) …”

“…(d) Line-cut extracted from GIWAXS map (red) and simulated X-ray diffraction pattern (black) of orthorhombic phase CsPbBr 3 . Reproduced with permission from ref . Copyright 2021 Wiley–VCH.…”

“…75 Recently, it was first demonstrated that one-step CVD could also be utilized to deposit millimeter-size CsPbBr 3 crystalline thin films with high phase purity, showing a promising preparation method suitable for PV applications (Figure 10c, d). 76 ■ AEROSOL-ASSISTED CVD (AACVD)…”

Vapor Phase Growth of Centimeter‐Sized Band Gap Engineered Cesium Lead Halide Perovskite Single‐Crystal Thin Films with Color‐tunable Stimulated Emission

“…[ 24 ] Nie's team obtained a millimeter‐scale orthorhombic phase CsPbBr 3 film with high‐crystallinity by vapor‐phase deposition, and they fabricated a lateral diode, significant photo‐generated voltages and short‐circuit currents were observed, indicating that the as‐growth CsPbBr 3 films had high crystallinity and admirable photoelectric properties. [ 25 ]…”