New Conjugated Polymer (PININE) with stability for LEDs

摘要

Fluorescent conjugated polymers have attracted much attention due to their potential applications in flat panel displays. There are few studies on the degradation of the PPV film in air when irradiated. The photodegradation reaction is a chain scission process involving oxygen in air to yield terminal 4-vinylbenzoic acid groups. The photodegradation of conducting polymer may seriously effect the performance of electroluminescence devices. In order to reduce oxidation of the vinylene group, the vinylic group was cyclized using carbon-containing 5-membered rings. In case of PININE, it is possible to introduce four alkyl groups in the sp3 carbons in the bicycle, which will increase the solubility of the polymer. PININE was used as the electroluminescence layer for the light-emitting diode. PININE shows turn-on voltage of 6.5 V, and EL with maximum peak at 477 nm, maximum brightness of 2187 cd/m~2 at 12 V, and efficiency of 0.34 cd/A at 162 mA/cm~2. The change in luminescence following irradiation with white light on the PININE was not observed. When irradiated with white light, the films of MEH-PPV showed significantly decreased peaks of UV and PL. As compared to this, the films of PININE showed stable spectra when irradiated over same period of time.