Organic wrinkles for energy efficient organic light emitting diodes

• Published in: Organic electronics Vol. 26; pp. 273 - 278
• Main Authors: Moon, Jaehyun, Kim, Eunhye, Park, Seung Koo, Lee, Keunsoo, Shin, Jin-Wook, Cho, Doo-Hee, Lee, Jonghee, Joo, Chul Woong, Cho, Nam Sung, Han, Jun-Han, Yu, Byoung-Gon, Yoo, Seunghyup, Lee, Jeong-Ik
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2015
• Subjects: Light extraction; Organic light emitting diodes; Spectral stability; Wrinkles; Spectral stability; Organic light emitting diodes; Light extraction; Wrinkles
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2015.07.046

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•We have synthesized a new type of liquid prepolymer, which spontaneously forms wrinkles upon UV light exposure.•We have demonstrated our wrinkles as a structure which can extract confined light in OLEDs and make them energy efficient.•Our wrinkles remove the viewing angle dependency of emission spectrum and stabilize the overall spectrum.
Extracting the confined light is of critical significance in achieving highly energy efficient organic light emitting diodes. To address the task of extracting the confined light, we here synthesize a new type of liquid prepolymer, which spontaneously forms wrinkles upon ultra-violet light exposure. The spontaneously formed organic wrinkle is successfully applied not only in extracting the confined light but also in inducing angular spectral stability. Simulations demonstrate that the wrinkles can lower incident angle of light impinging on the substrate/air interface and thus help extract a large portion of light delivered to the substrate. In particular, it is shown that geometrical optimization of the size and aspect ratio of wrinkles is important in obtaining the highest light extraction. With the simplicity of the process and size controllability, the proposed wrinkle-based approach can be readily realized over a large area, opening up a new avenue in various photonics applications.