Synthesis,Photo-,and Electroluminescent Properties of the Soluble Poly[(2,5-diphenylene-1,3,4-oxadiazole)-4,4'-vinylene]

摘要

A novel soluble conjugated polymer,poly[(2,5-diphenylene-1,3,4-oxadiazole)-4,4'-vinylene] (O-PPV),containing an electron-transporting group on the main chain of PPV,was synthesized according to HORNER mechanism.The oligo-polymer with M_w = 1000 and T_#alpha# =270 deg C is soluble in chloroform and tetrahydrofuran.The photoluminescent (PL) properties were investigated using different concentrations of solid-state O-PPV/PEO blends absorption and selective excitation measurements.The results show that PL arises from interchain charge-transfer states in solid-state O-PPV.Compared with the analogous single-layer device constructed with PPV (ITO/PPV/Al),which emits two peaks at #lambda# = 520 nm and 550 nm (shoulder),the electroluminescence (EL) spectrum of the device [ITO/O-PPV (80 nm)/Al] is a broad peak at #lambda#_(max) = 509 nm.The quantum efficiency (0.13%) of the device IO/O-PPV/Al is much higher than that of the device ITO/PPV/Al,due to the introduction of the electron-transporting group-oxadiazole units in the main chain of PPV.