Fig. 1. μPL spectra following excitation at 543 nm of the (a) Glass/CH₃NH₃PbI₃, (b) Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃ and (c) Glass/ITO/PTAA/CH₃NH₃PbI₃ architectures.

Fig. 2. Shift of the μPL emission peak as a function of temperature for (a) Glass/CH₃NH₃PbI_3,(b) Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃ and (c) Glass/ITO/PTAA/CH₃NH₃PbI₃ architectures for the orthorhombic (red solid circles) and tetragonal (blue solid circles) perovskite crystal phases.

Fig. 3. FWHM of the PL peaks corresponding to the orthorhombic (black diamonds) and tetragonal (red circles) phases of CH₃NH₃PbI₃ as a function of temperature (a) Glass/CH₃NH₃PbI₃, (b) Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃ and (c) Glass/ITO/PTAA/CH₃NH₃PbI₃. Green solid lines show the fitting acquired by the temperature-independent inhomogeneous broadening (Γ₀) and the interaction between charge carriers and longitudinal optical phonons (LO-phonons), as described by the Fröhlich Hamiltonian.

Fig. 4. Optical density (ΔOD) vs. wavelength at various delay times for Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃ architecture at (a) 85 K, (b) 120 K and (c) 180 K.

Fig. 5. Optical density ΔOD vs. wavelength at various delay times for Glass/ITO/PTAA/CH₃NH₃PbI₃ configuration at (a) 85 K, (b) 120 K and (c) 180 K.

Fig. 6. Optical density (ΔOD) peaks wavelength as a function of temperature for Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃ architecture and Glass/ITO/PTAA/CH₃NH₃PbI₃configurations, as extracted from TAS spectra at t = 0 ps (see Fig. 4 and Fig. 5 blue lines).

Fig. 7. Normalized optical density (ΔOD) vs. delay time for Glass/ITO/PEDOT:PSS/CH₃NH₃PbI₃and Glass/ITO/PTAA/CH₃NH₃PbI₃configurations for the orthorhombic phase at (a) 85 K, (b) 120 K and for the tetragonal phase at (c) 120 K and (d) 180 K. Symbols present the transient band edge bleach kinetics, while solid lined present the decay exponential fitting. Insets are shown the initial time scale for Glass/ITO/PTAA/CH₃NH₃PbI₃.

Table 1. Time components and bimolecular recombination rate (k₂) for the Glass/ITO/PEDOT:PSS/CΗ₃NΗ₃PbΙ₃ and Glass/ITO/PTAA/CH₃NH₃PbI₃ architectures.