ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 45, Number 2
JKCSEZ 45(2)
April 20, 2001 

Various oxidation states of Polyaniline(PANI) were chemically synthesized, and characterized by FT-IR, UV-Vis, GPC, TG-DTA. Single layer light emitting diodes(LED) were prepared by spin coating of LEB-PANI solutions which have various oxidation states onto an ITO substrate and subsequent vacuum deposition of aluminum top electrode and then current-voltage characteristics, EL spectrum was investigated. It was found that π→π^* transition were shifted to longer wavelength and molecular exciton transition were decreased in the UV-Vis spectra and the intensity of EL and PL were increased as the contents of fully reduced form LEB increased. The turn-on voltage of ITO/LEB/Al structured LED was 5 V. It was found that the white light was emitted only from the phase with reduced repeat unit.