light sources;
heterojunctions;
poly(phenylene-vinylene) and derivatives;
D O I:
10.1016/S0379-6779(97)80239-1
中图分类号:
T [工业技术];
学科分类号:
08 ;
摘要:
We have fabricated organic LEDs with mobile ions incorporated into the active polymer layer, similar in structure to the electrochemical cells (LECs) reported by Pei et al. We report characteristics for devices with ionic concentrations < 10(17) cm(-3), which show rectifying characteristics We show that device behaviour can be understood solely in terms of an electrostatic model. The accumulation of ionic space-charge in the vicinity of the two electrodes is shown to permit easier injection of electronic carriers than is possible in a conventional LED. The device characteristics are strongly dependent on ionic concentration. Rectification is predicted at low ionic concentrations, switching to symmetrical behaviour at higher concentrations.