Photoelectric phenomena in polymer-based composites

We consider photoelectric phenomena in a composite medium in which inclusions form a type-II heterojunction with a host matrix. The model describes, in 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 effect is observed experimentally in a wide range of polymer-based composites with disparate inclusions. For photodiode structures, this same phenomena either does not change, or slightly decrease, the quantum yield. (C) 2000 American Institute of Physics. [S0021- 8979(00)03719-1].