A novel patterning technique for high-resolution RGB-OLED-displays: Laser induced local transfer (LILT)

A novel patterning technique for high-resolution full-color OLED-displays will be discussed. Currently applied production systems for OLED-displays incorporate a shadow masking system for patterning of single red, green and blue pixels. Due to its limited scalability, alternative techniques, which can be applied to larger substrate sizes, have to be developed. One approach can be the laser induced local transfer of organic materials.An infrared absorbing substrate (target) is coated with either a red, green or blue light-emitting organic material and placed in a short distance (below 50 νm) of the OLED-substrate onto which the organic material is to be patterned. The laser beam is deflected by a scanner onto the target in single lines. If the scanning speed and the laser power are adjusted properly, the target locally heats up to a temperature at which the organic material sublimes and condenses on the opposing OLED-substrate. By repeating this process for each colour red, green and blue stripes can be deposited. Line widths below 70 νm have been achieved.