In our previous papers, we reported the synthesis of various poly(3-al
kylthiophenes) derivatives with different side chain length, fabricati
on of their Langmuir-Blodgett films, conductivities and Schottky diode
s. Here, we extend our research to their electroluminescent properties
. Multilayer Light-emitting diodes composed of poly(3-octylthiophene)
as light-emitting layer and hole transport layer are constructed. The
current-voltage and brightness-voltage characteristics as well as the
electroluminescent spectra are investigated and discussed.