Design of white tandem organic light‐emitting diodes for full‐color microdisplay with high current efficiency and high color gamut

• Published in: ETRI journal Vol. 43; no. 6; pp. 1093 - 1102
• Main Authors: Cho, Hyunsu, Joo, Chul Woong, Choi, Sukyung, Kang, Chan‐mo, Kim, Gi Heon, Shin, Jin‐Wook, Kwon, Byoung‐Hwa, Lee, Hyunkoo, Byun, Chun‐Won, Cho, Nam Sung
• Format: Journal Article
• Language: English
• Published: Electronics and Telecommunications Research Institute (ETRI) 01.12.2021; 한국전자통신연구원
• Subjects: color gamut; microdisplay; organic light‐emitting diode; tandem OLED; white OLED; 전자/정보통신공학
• ISSN: 1225-6463; 2233-7326
• DOI: 10.4218/etrij.2020-0321

Microdisplays based on organic light‐emitting diodes (OLEDs) have a small form factor, and this can be a great advantage when applied to augmented reality and virtual reality devices. In addition, a high‐resolution microdisplay of 3000 ppi or more can be achieved when applying a white OLED structure and a color filter. However, low luminance is the weakness of an OLED‐based microdisplay as compared with other microdisplay technologies. By applying a tandem structure consisting of two separate emission layers, the efficiency of the OLED device is increased, and higher luminance can be achieved. The efficiency and white spectrum of the OLED device are affected by the position of the emitting layer in the tandem structure and calculated via optical simulation. Each white OLED device with optimized efficiency is fabricated according to the position of the emitting layer, and red, green, and blue spectrum and efficiency are confirmed after passing through color filters. The optimized white OLED device with color filters reaches 97.8% of the National Television Standards Committee standard.