Researchers Use 3D OLED Pixel Structure to Increase Efficiency by 30%

Researchers in Taiwan have developed a 3D pixel structure for OLED devices that enable to improve light extraction. It allows to increase the external quantum efficiency of top-emitting OLED devices to 30%.



The new design adopts a 3D reflective pixel structure filled with patterned materials of high refractive index. The researchers create pixels of different sizes and find that the smaller the pixel, the greater the efficiency improvement.


The researchers take advantage of the concave structure on a conventional AMOLED pixel and modify the integration process so that the bottom of reflective anode extends over the pixel slope to create a pixel emission region. The high-refractive-index material is further selectively filled in the concave pixel regions by vacuum evaporation through tiny openings in the aligned FMM, completing the reflective 3D pixel structure.


The researchers say that even greater efficiency could be achieved by further improving the 3D pixel structure, such as by employing a transparent electrode to reduce optical losses.