Fig. 1
Power-dependent photoluminescence spectra of the FASnI3 thin film. a Normalized PL spectra of FASnI3 with excitation fluence increasing from 0.03 to 34 μJcm−2 at 293 K. b 2D pseudo-color plot of normalized PL spectra as a function of excitation power, showing the blue shift as the excitation density increases. The emission energy shifts from 1.38 to 1.46 eV at 293 K (with similar conditions the shifts are equal to 17 meV for FAPbI3, 6.5 meV for MAPbI3 and 4 meV for MAPbBr3). c Logarithmic plot of the integrated intensity of the emission as a function of power density—a linear dependence (red line) at low excitation fluence is observed at 293 K. d Power-dependent PL spectra of FASnI3 at 24 K. e 2D pseudo-color plot of normalized PL spectra as a function of excitation power, PL blue shift from 1.23 to 1.39 eV at 24 K. f Integrated PL intensity as a function of power density at 24 K
