Vacuum-deposited, nonpolymeric flexible organic light-emitting devices

We demonstrate mechanically flexible, organic light-emitting devices (OLED's) based on the nonpolymetric thin-film materials tris-(8-hydroxyquinoline) aluminum (Alq(3)) and N, N'-diphenyl-N,N'-bis(3-methylphenyl)1-1'biphenyl-4 4' diamine (TPD. The single heterostructure is vacuum deposited upon a transparent, lightweight, thin plastic substrate precoated viith a transparent, conducting indium tin oxide thin film. The flexible OLED performance is comparable with that of conventional OLED's deposited upon glass substrates and does not deteriorate after repeated bending. The large-area (similar to 1-cm(2)) devices can be bent without failure even after a permanent fold occurs if they are on the convex substrate surface or over a bend radius of similar to 0.5 cm if they are on the concave surface. Such devices are useful for ultralightweight, flexible, and comfortable full-color flat panel displays. (C) 1997 Optical Society of America