Time-resolved spectroscopy of radiative energy transfer between a conjugated oligomer and polymer in solution

We report a short investigation of the energy transfer process between the conjugated oligomer 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) and the conjugated polymer poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene-vinylene] — end capped with DMP (MDMO-PPV). The radiative energy transfer (RET) process shows a time delay, and the formation of the excimer causes a further delay. All these processes were studied using time-resolved spectroscopy (TRS), which has three-dimensional (3D) features with wavelength, intensity and time (picosecond) as the X, Y and Z-axis, respectively. We observed a definitive delay (1 ns) in the fluorescence from MEDMO-PPV concerning the fluorescence of the oligomer, indicating the RET. The TRS of different relative concentrations and temperature effects on the energy transfer process was also studied. The quantum yield, critical distance, polarizability and change of MEDMO-PPV were calculated. The excimer of the MEDMO-PPV produces Amplified Spontaneous Emission (ASE) after a time delay of at least 0.5 ns, which was also observed in this study. [Display omitted] •The spectral properties of conjugated polymer MDMO-PPV — end-capped with DMP were studied.•The radiative energy transfer mechanism from a CO BECV-DHF, and the CP MDMO-PPV in toluene solution was presented.•The TRS of different relative concentrations and temperature effects on the energy transfer process was studied.•The TRS results of the energy transfer process demonstrate the formation of monomer ASE and excimer species in CP MDMO-PPV.