High-speed electroluminescence modulation of a conjugated-polymer light emitting diode

To maximize the electroluminescence (EL) switching rate that can be generated in an organic-based light emitting diode, we fabricated a device having an active area of 0.018 mm(2) which is based on a 1:1 blend of the high charge-carrier mobility conjugated polymers poly[dioctylfluoreneco-N-(4-butylphenyl) diphenylamine] and poly[9,9(')-dioctylfluorene-co-benzothiadiazole]. Our devices have a 50% cutoff frequency of 26 MHz and a maximum EL modulation rate of 63 MHz at a drive voltage of 3.8 V. Such switching rates are suitable for short-range video transmission via plastic optical fibers, suggesting possible applications as optical communication light sources.