光色稳定的聚合物白光器件

Bright and efficient white-polymeric light-emitting diodes (WPLED) were fabricated using poly(2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene) (MEH-PPV) doped in poly(fluorene) (PF) with an architecture of ITO/PEDOT/MEH-PPV : PF(0.6wt%)/Ba/Al. At low doping level, blue emission from PF and yellow emission from MEH-PPV were co-existed in photoluminescence (PL) spectra, because of incomplete energy transfer from the PF to the MEH-PPV. When the weight ratio of the PF to the MEH-PPV is set at 0.6%, the device exhibits a stable white electroluminescence (EL) with CIE coordinate from (0.36, 0.36) to (0.32,0.35) and brightness from 200 cd/m2 to 20000 cd/m2 as the forward bias increases from 5 V to 13 V. The device characterizations show that the EL turn-on voltage is below 6 V and the maximum luminance reaches 20000 cd/m2 at the bias of 10 V. The luminous power efficiency and luminous efficiency were found to be about 2.2 lm/W and 4.2 cd/A, respectively, at the bias of 4 V.