Figure 4
Diffuse reflectance spectra, UPS spectrum, and schematic energy profile for (CH 3 CH 2 NH 3 )PbI 3 . Diffuse reflectance spectra and the transformed Kubelka-Munk function for (a, b) the bare TiO2, (c, d) the powdered (CH3CH2NH3)PbI3, and (e, f) the (CH3CH2NH3)PbI3 deposited on TiO2. (g) UPS spectrum and (h) schematic energy profile for (CH3CH2NH3)PbI3. In UPS spectrum, binding energy was adjusted with respect to He-I (21.22 eV).