Using angle-selective optical film to enhance the light extraction of a thin-film encapsulated 3D reflective pixel for OLED displays
Journal
Optics Express
Journal Volume
30
Journal Issue
26
Date Issued
2022-12-19
Author(s)
Liao, Po Hsiang
Lee, Wei Kai
Lee, Chang Cheng
Huang, Chun Wei
Wen, Sheng Wen
Chen, Yi Ting
Chen, Chung Chia
Lin, Wan Yu
Kwak, B. Leo
Visser, Robert Jan
Abstract
Light extraction improvement is still an important issue for active-matrix organic light-emitting diode displays (AMOLEDs). In our previous work, a three-dimensional (3D) reflective pixel configuration embedding the OLED in the concave 3D reflector and patterned high-index filler had been proposed for significant enhancement of the pixel light extraction. In this work, influences of thin film encapsulation (TFE) on light extraction of such reflective 3D OLED pixels are considered as well by simulation studies. Unfortunately, the optical simulation reveals strong reduction of the light extraction efficiency induced by TFE layers. As such, an additional angle-selective optical film structure between the pixel and the encapsulation layers is introduced to control the angular distribution of the light coupled into the encapsulation layers and to solve TFE-induced optical losses. As a result, TFE-induced losses can be substantially reduced to retain much of light extraction efficiency. The results of this study are believed to provide useful insights and guides for developing even more efficient and power-saving AMOLEDs.
SDGs
Type
journal article