PREPARATION OF POLYIMIDE LANGMUIR-BLODGETT-FILMS POSSESSING A TRIPHENYLAMINE UNIT AND THEIR APPLICATION TO PHOTODIODES

Photoconductive devices (photodiodes) were constructed by the deposition of polyimide LB multilayer films which possessed different chemical structures, i.e., a triphenylamine unit as an electron donor (D), tetraphenylporphyrin as a sensitizer (S), and aromatic polyimide as an electron acceptor (A). Two types of photodiodes with E/D/S/A and E/A/S/D systems were prepared on a semitransparent gold electrode (E). The dependence of each number of D, S, and A layers on the photocurrent behavior was examined to discuss the electron transfer in each layer.