Fig. 5. Broadband white-light emission of P-DT upon 345 nm excitation: (a) emission spectra of P-DT in toluene at room temperature (RT) and at 77 K. The purple and green-yellow dashed boxes here were marked to highlight the appearance of the bands at nearly the same wavelength. (b) Emission spectra of P-DT in toluene at 77 K with delay. (c) Proposed mechanism for the long-lifetime broadband emission of P-DT or P-DT2. (d) CIE 1931 chromaticity diagram. The red dot 1 signifies the luminescent color coordinate (0.25, 0.36) for the corresponding state in (a), while the black dots feature the luminescent color coordinates for the corresponding states in Fig. 3b, 2 (0.28, 0.42), 3 (0.26, 0.35) and 4 (0.19, 0.20).
