Ultrafast study of charge generation in silole:fluorene mixed film for color selective organic photoconductive device

Transient absorption characteristics of blue‐sensitive organic thin films were investigated via a femtosecond pump‐probe technique to estimate carrier kinetics. The most important finding is that the long‐lived absorbance at 3440 nm increased with increasing the concentration of 1,1‐dimethyl‐2,5‐bis(N,N ‐dimethylaminophenyl)‐3,4‐diphenylsilole (NMe2‐silole). This fact indicates photo‐excited carriers were dislocated in the organic layer, and the doping of NMe2‐silole is considered to be useful method to improve photoconductive characteristics of organic devices (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)