Abstract
The ternary hybrid thin films of poly [9,9 '-di-n-octylfluorenyl-2,7-diyl] (PFO)/poly [2methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)/2-butyl-6(butylamino) benzo [de] isoquinoline-1,3-dione (F7GA) were successfully prepared with various ratios of F7GA. Dual Fodrster resonance energy transfer (FRET) from PFO to both F7GA and MEH-PPV was confirmed in the ternary thin films. The distance between PFO and F7GA molecules was smaller than the distance between PFO and MEH-PPV. Besides, white light emission was achieved with cascade energy transfer in this ternary blend system. The lifetime decay components of the acceptor emission were attributed to the presence of an exciplex between the molecules in the acceptor excited state and the donor ground state. In addition to the dual FRET, carrier trapping took place in the device, successfully realizing white organic light-emitting diodes (WOLEDs). The maximum luminance of 2295 cd/m(2) and a current density of 12.98 mA/cm(2) at CIE coordinates of (0.31, 0.24) was achieved with the device at 1.0 wt% F7GA.