a The side view of the absorbance-wavelength plot for the transient UV–Vis character of rac-BINAP in vacuum deposit film on quartz recorded at different delayed time. λex = 355 nm. b The absorbance-wavelength plot for the transient UV–Vis character recorded at 50 ns delayed time of rac-BINAP solid film. Also shown is the photoluminescence spectrum (red solid line) of rac-BINAP in solid film. c Relative EL spectra at different operated voltage. d The phosphorescence (Phos., red dot) and fluorescence (Fluor., blue dot) intensity as a function of the operated current density and the corresponding fitting curves.