COLD PHOTOCONDUCTIVITY IN A SYSTEM OF INTERACTING CHARGE-TRANSFER EXCITONS AT A DONOR-ACCEPTOR INTERFACE

Computer simulations are used to investigate the phase transition to t he conducting state in a system of interacting 2D charge-transfer exci tons (CTEs) at a donor-acceptor interface. The phase transition arises due to strong dipole-dipole repulsion between CTEs which stimulates t he population of free carriers in higher energy states even at low tem perature. The random distribution of excitons and finite Lifetime is e xplicitly taken into account. The critical concentration of CTEs and t heir energy distribution is calculated. Some features of spatial order ing of CTEs at the interface are considered. We also discuss the possi bility of observing the predicted phenomena. (C) 1998 Elsevier Science B.V. All rights reserved.