Bright‐Multicolor, Highly Efficient, and Addressable Phosphorescent Organic Light‐Emitting Fibers: Toward Wearable Textile Information Displays

• Published in: Advanced functional materials Vol. 31; no. 18
• Main Authors: Hwang, Yong Ha, Kwon, Seonil, Shin, Jeong Bin, Kim, Hyuncheol, Son, Young Hyun, Lee, Ho Seung, Noh, Byeongju, Nam, Minwoo, Choi, Kyung Cheol
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.05.2021
• Subjects: Brightness; Current efficiency; Displays; fibertronics; fiber‐based light‐emitting diodes; Form factors; Formability; Immersion coating; Low currents; Materials science; Optoelectronics; Organic light emitting diodes; Phosphorescence; Power consumption; textile display; wearable display; Wearable technology
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202009336

Fiber‐based light‐emitting devices, which can be directly integrated into daily clothes, have emerged as a next‐generation display form factor that can provide informational hyper‐connections between humans and devices. However, although various approaches have provided advanced wearability, challenges remain for visualizing information, such as high power consumption resulting from high driving voltage and low current efficiency (CE), limited brightness making information difficult to recognize, and lack of addressability for displaying information. Here, a novel fiber‐based textile display that can surmount those challenges by successfully introducing phosphorescent organic light‐emitting diodes (phOLEDs) based on a dip‐coating method and an addressable structure on cylinder‐shaped fiber is reported. The fiber phOLEDs exhibit unprecedented optoelectronic performance, including brightness, CE, and driving voltages comparable to those of conventional glass‐based OLEDs. Particularly, they show the highest CE values of 16.3, 60.7, and 16.9 cd A–1 for red, green, and blue, respectively, among results reported thus far. Also, the fiber phOLEDs with an addressable structure implementing independent pixels can be operated by the matrix‐addressable scheme. Based on unique deformability which is confirmed by flexibility tests, the performance capabilities, and addressability, letter information can be successfully visualized on daily clothes, demonstrating the potential for realizing truly wearable textile displays. Although the fiber‐based light‐emitting devices reported so far show advanced wearability, challenges remain for visualizing information beyond merely the emission of light. To address the aforementioned challenges, RGB fiber phOLEDs with unprecedented optoelectronic performance including distinguishable brightness, highest current efficiency values among results reported thus far, low driving voltage, and a matrix‐addressable scheme are reported.