Synthesis, photo-, and electroluminescent properties of the soluble poly[(2,5-diphenylene-1,3,4-oxadiazole)- 4,4′-vinylene]

✍ Scribed by Shougen Yin; Zhenjia Wang; Xiaohui Yang; Wenqiang Huang; Fuqiang Zhang; Xurong Xu

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 177 KB
• Volume: 74
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19991227)74:14<3535::aid-app29>3.0.co;2-1

✦ Synopsis

A novel soluble conjugated polymer, poly[(2,5-diphenylene-1,3,4-oxadiazole)-4,4Ј-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 ϭ 1000 and T d ϭ 270°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 ϭ 520 nm and 550 nm (shoulder), the electroluminescence (EL) spectrum of the device [ITO/O-PPV (80 nm)/Al] is a broad peak at max ϭ 509 nm. The quantum efficiency (0.13%) of the device ITO/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.