Tuning of chromaticity in organic multiple-quantum well white light emitting devices

We fabricate organic multiple-quantum wells structure (MQWs) white light-emitting diodes (LEDs), in which blue fluorescent phenylpyridine beryllium (BePP2), orange fluorescent rubrene doped green fluorescent aluminum complex (Alq(3)) act as MQWs light-emitting layers between potential barriers triphenyldiamine derivative (TPD). Excitons are confined in different MQWs light-emitting layers due to higher bandgap E-g of TPD. The Commission Internationale de l'Eclairage (CIE) coordinates of the emitted light are tuned by changing the well number ratio of BePP2 to Alq:rubrene. The organic MQWs white LEDs with three BePP2 wells show excellent optical and electrical performance. The CIE coordinates of the emitted light vary from (0.42, 0.38) to (0.34, 0.34) when forward voltages change from 7 to 13 V, which are just near to the white-light equi-energy point (0.33, 0.33). The brightness and luminous efficiency are 611 cd/m(2) and 0.34 lm/W at 12 V, respectively. (C) 2000 Elsevier Science S.A. All rights reserved.