Figure 1.
Characterizations of slot-die coated perovskite films on indium tin oxide (ITO) coated glass substrates covered with hole transporting materials (here self-assembled monolayer molecule “’2PACz’”) prepared at various annealing temperatures as indicated. (A) Top-view SEM images showing the perovskite domain size and surface composition distribution; the scale bar in part A applies to all SEM images. The first row is acquired by the secondary electron detector (SE2) showing the halide perovskites topography with high lateral resolution. The second row was recorded using the InLens detector (SE1) which enhances the surface compositional contrast. (B) Grain radius distribution as derived from the first row in panel A. The mean area equalized grain radius (Ravg) indicates an increased grain size for higher annealing temperatures. Inset: Angular X-ray diffraction (XRD) patterns, rescaled to allow for better comparison of peak positions. (C) UV–vis spectra to show the shift of the absorption edge with annealing temperatures. (D) Photoluminescence (PL) measurement statistics show that samples annealed at 150 °C have the highest calculated QFLS. (E) Corresponding PL spectra. (F) Time-resolved photoluminescence (trPL) transients, showing the slowest nonradiative recombination for a film annealed at 150 °C.