Highly improved light extraction with a reduced spectrum distortion of organic light-emitting diodes composed by the sub-visible wavelength nano-scale periodic (鈭?50 nm) structure and micro-lens array

详细信息    查看全文

• 作者：Kyung Bok Choi ; Se Joong Shin ; Tae Hyun Park ; Hyun Jun Lee ; Ju Hyun Hwang ; Jung Ho Park ; Bo Yeon Hwang ; Young Wook Park ; Byeong-Kwon Ju
• 关键词：Laser interference lithography (LIL) ; Organic light-emitting diodes (OLEDs) ; Nano-scale periodic pattern ; Out-coupling ; Micro-lens arrays ; Photonic crystal
• 刊名：Organic Electronics
• 出版年：January, 2014
• 年：2014
• 卷：15
• 期：1
• 页码：111-117
• 全文大小：1632 K

文摘

Out-coupling enhanced organic light-emitting diodes (OLEDs) with micro-lens arrays and a nano-scale periodic light-extraction structure鈥攁 photonic crystal (PC)鈥攗tilizing laser interference lithography (LIL) are demonstrated. Generally, PC-based OLEDs suffer from a distorted and shifted spectrum, despite a highly improved intensity. However, in this study, we demonstrate PC-based OLEDs with a distortion-free spectrum and a highly improved out-coupling performance. It was found that spectrum distortion decreased with the pitch size of the PC. The PC-based OLED with a 250 nm pitch size showed a dramatically reduced spectral shift: International Commission on Illumination 1931 color coordinate of (螖0.00, 螖0.00) and 螖peak wavelength of 0 nm as compared with the reference. Simultaneously, the external quantum efficiency and the power efficiency were enhanced by up to 178% and 264%, respectively, as compared with the reference. Moreover, through the LIL, simple and maskless processes were achieved for a light-extraction structure over a large area.