Photoelectric phenomena in polymer-based composites

We consider photoelectric phenomena in a composite medium in which inclusio ns form a type-II heterojunction with a host matrix. The model describes, i n particular, polymer-based photosensitive structures with different types of semiconducting or insulating inclusions. It is shown that the separation on nonequilibrium carriers due to interface electric fields increases the hole component of photoconductivity, decreases the electron component, and results in a substantial increase of the total photoconductivity. The effec t is observed experimentally in a wide range of polymer-based composites wi th disparate inclusions. For photodiode structures, this same phenomena eit her does not change, or slightly decrease, the quantum yield. (C) 2000 Amer ican Institute of Physics. [S0021- 8979(00)03719-1].