Microcavity devices based on a ladder-type poly(p-phenylene) emitting blue, green, and red light

Light emitting devices with emission either in the blue, green, and red spectral region have been fabricated based on ladder-type poly(p-phenylene) (LPPP). Color tuning has been achieved simply by adjusting the LPPP layer thickness. Microcavity effects could be proven to control the shape of the electroluminescence and photoluminescence spectra of the single layer devices between aluminum and gold electrodes. The full width at half-maximum was strongly reduced from similar to 150 to 200 nm for the ''free space'' photoluminescence or for the electroluminescence spectra of devices with indium-tin oxide hole injecting electrodes to values between 60 and 70 nm for the three individual single color devices. (C) 1996 American Institute of Physics.