Fig. 4: Optical and electronic properties.

a UV-vis diffuse reflection spectrum of Py-DAB and PyN-DAB (Inset: the optical band gaps of Py-DAB and PyN-DAB according to the Kudelka-Munk-transformed reflectance spectra). b PL lifetime decay spectra of Py-DAB and PyN-DAB. c EIS curves of Py-DAB and PyN-DAB. d Photocurrent generation test spectrum of Py-DAB and PyN-DAB.