Direct observation of ultrafast field induced charge photogeneration in conducting polymers

Summary form only given.We investigate field-induced charge generation by applying the femtosecond pump-probe technique to LEDs made with methyl-substituted ladder-type poly(para-phenylene) (m-LPPP). These LEDs consist of thin films of m-LPPP (about 100 nm thick) are sandwiched between aluminium and transparent ITO electrodes. Pump and probe pulses, of about 150 fs duration, reached the m-LPPP film.