Fabrication of organic light-emitting devices on flexible substrates using a combined roller imprinting and photolithography-patterning technique

A patterning method has been developed to fabricate patterned organic light-emitting devices (OLEDs) (60×80mm2) with a pixel size of 500×300μm2 on flexible polyethylene terephthalate substrates. The patterns of the pixel array were defined in crossed-strip style with indium tin oxide anode and patterned using a combination of roller-type imprinting lithography and photolithography (CRIP) followed by wet etching. Compared with conventional imprint lithography or photolithography, the CRIP technique has the advantages of better uniformity, less force, consuming less time, lower cost, and higher aspect ratio. The performance of the CRIP OLEDs was the following: the turn-on voltage at 1cd∕m2 was 7.5V and the maximum luminance was 13530cd∕m2 at 17.5V. The highest luminous efficiency reached 1.27lm∕W (3.23cd∕A) at a luminance of 4.8cd∕m2 and kept the values stable from 5to15V. The performance was comparable to that of devices patterned by conventional photolithography.