The merchanism of fluorescence quenching of rhodamine 6G (R6G) by 2,5-bis( p-diethylaminophenyl)-1,3,4-oxadiazole (photoconductor, PC) in polymer binders was studied for both single and double layers (thickness, 5–10 μm) in the system R6G—PC—polymer. In single layers R6G and PC are dissolved in one polymeric binder, whereas in double layers PC and R6G are separated from each other and dissolved in two different polymeric binders. The fluorescence quenching in these layers is explained by singlet exciton reactions. Here, excitons are considered as mobile quasi-particles. In contrast with electrons and holes these particles are uncharged. Excitons generated on R6G sites can migrate in these layers until they decay either radiatively or non-radiatively or until they become trapped. In single layers, singlet exciton trapping probably proceeds via the intermediate state of ▪. This state is characterized by pairs of countercharges positioned on these molecules and is termed a charge transfer (CT) exciton. The rate constant k of the formation of this exciton depends on the R6G—PC distance R (in nanometres) and obeys the equation ▪ in the binder of the propyl-halfester f copolymeric styrene—maleic anhydride (ST—MSA). In double layers the singlet exciton trap process is different from that in single layers. Here, the trapping of singlet excitons takes place in a finite volume near the interface of the double layer structure and leads to trapped electron—hole pairs localized on different PC molecule sites. From fluorescence quenching experiments in double layers the following rate constants were obtained: k = (4 ± 1) × 10 8 s −1 for the self-trapping of singlet excitons, k = (4 ± 0.5) × 10 −12 cm 3 s −1 for the exciton annihilation 1Ex * + 1Ex * and k = (9.5 ± 0.5) × 10 −13 cm 3 s −1 for the reaction between singlet excitons and PC traps. From xerographic discharge measurements it is observed that the charge decay rate is independent of the sign of the surface charge (positive or negative) of the layers and increases with the PC trap concentration. Furthermore, xerographic discharge and fluorescence quenching experiments demonstrate that charge carriers are generated in single layers by dissociation of the CT exciton ▪ and in double layers by the exciton trap process ▪