Light emitting diode based on p-phenylene vinylene oligomer

Summary form only given. Light emitting diodes(LEDs) have been constructed using a kind of p phenylene vinylene oligomer with two different film coating techniques. One of them was the usual spin coating method, coated on to the ITO/glass substrate from a chloroform solution with 5:1 mixing ratio(by weight) of oligomer and PMMA(poly(methyl methacrylate)). Another was the thermal evaporation of oligomer itself (5mg) directly on to the ITO/glass substrate inside the vacuum chamber with boat temperature ranged from 80 to 150/spl deg/C. In both cases, Sr was sputtered prior to the final metal evaporation with In, yielding In/Sr/oligomer/ITO/glass LED structure with active areas about 2CM/sup 2/. Our devices show visible blue emission at room temperature with electroluminescence (EL) spectrum similar to that of photoluminescence(PL). The temperature dependent I-V characteristics and stability as well as comparison of the EL and PL spectra of devices fabricated by both film coating methods will be discussed.