Fig. 2

Time-resolved photoluminescence in mixed solvents. a Normalized time-resolved photoluminescence (TRPL) spectra recorded at various time delays for a solution of D-PDPP4T-HD in 1:0, 3:7 and 0:1 (v/v) of chloroform:1,2,4-trichlorobenzene (CF:TCB). The polymer concentration is 0.4 µM. Excitation was performed at 800 nm with 80 MHz laser pulse repetition rate. A 808 nm long-pass filter was used to suppress the scattered laser pulse. b Emission dynamics of α phase from 0:1 solution at 100 °C with λ_ex =400 nm and λ_em =815–865 nm, β₁ phase from 1:0 solution with λ_ex =800 nm and λ_em =825–840 nm, and β₂ phase from 0:1 solution with λ_ex =800 nm and λ_em =870–890 nm