Fig. 4
Photophysical properties of the CsBr- and CsTFA-derived CsPbBr3 perovskite films. a Absorption and b PL spectra of the CsBr(1.7)- and CsTFA(1.7)-derived CsPbBr3 perovskite films. Inset in b shows the photograph of the green-emitting perovskite films, taken under UV lamp excitation. c, d Transient absorption maps of the CsBr(1.7)-derived and CsTFA(1.7)-derived films, respectively. Pump wavelength and pump pulse width are 365 nm and 100 fs, respectively. The red arrows indicate the trajectory of the bleach minimum position. ΔA represents optical density. e Shifts of the bleach minimum position over time for the two types of the CsBr(1.7)- and CsTFA(1.7)-derived films. f Time-resolved PL decay curves of the CsBr(1.7)- and CsTFA(1.7)-derived films on ITO/PEDOT:PSS substrates
