Novel stretchable light‐emitting diodes based on conjugated‐rod block elastic‐coil copolymers. Issue 4 (30th April 2020)

• Record Type: Journal Article
• Authors: Jao, Chih‐Chun; Chang, Jia‐Rui; Ya, Chia‐Yu; Chen, Wei‐Cheng; Cho, Chia‐Jung; Lin, Ja‐Hon; Chiu, Yu‐Cheng; Zhou, Ye; Kuo, Chi‐Ching
• Is Part Of: Polymer international. Volume 70:Issue 4(2021)
• Page Start: 426
• Page End: 431
• Publication Date: 2020-04-30
• Subjects: polyfluorene -- poly(isoprene) -- rod–coil block copolymers -- stretchable -- light‐emitting device; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1002/pi.6023
• Languages: English
• ISSNs: 0959-8103

Abstract

Abstract : In this study, we successfully fabricated an intrinsically stretchable light‐emitting diode (LED) by using a new conjugated rod–coil block copolymer, poly[2, 7‐(9, 9‐dioctylfluorene)]‐block‐poly(isoprene) (PF‐b‐PI). ( PF conjugated rods and PI coils exhibited fluorescent and intrinsically stretchable properties, respectively. Copolymers with three different rod/coil ratios, namely PF18K ‐ b ‐PI5K, PF12K ‐ b ‐PI5K and PF12K ‐ b ‐PI10K, were utilized for elastic LED demonstration. Notably, PF18K ‐ b ‐PI5K and PF12K ‐ b ‐PI5K LEDs can work under a strain of 140% because of suitable ratios of rod/coil lengths. Finally, a stretchable PF12K ‐ b ‐PI5K LED was measured with a low voltage of 2 V and with a brightness of 70 cd m −2 at 10 V. This LED was subjected to 100 cycles of luminance–strain testing under 50% strain and it maintained a stable level of brightness. These results demonstrated that the luminescent PF12K ‐ b ‐PI5K rod–coil block copolymers exhibit exceptional stretchability and high stability; these copolymers can be used in stretchable LEDs for a wide range of applications. © 2020 Society of Chemical Industry Abstract : A novel stretchable light‐emitting diode (LED) using a new conjugated rod–coil block copolymer, poly[2, 7‐(9, 9‐dihexylfluorene)]‐ block ‐poly(isoprene) (PF‐ b ‐PI), was investigated. It can work under a strain of 140%. Moreover, it was subjected to 100 cycles of luminance–strain testing under 50% strain and it maintained a stable level of brightness.