Huanyu Zhou1,Shin Jung Han1,Amit Kumar Harit2,Dong hyun Kim2,Dae Yoon Kim3,Yong Seok Choi3,Hyeokjun Kwon1,Kwan-Nyeong Kim1,Gyeong-Tak Go1,Hyung Joong Yun4,Byung Hee Hong3,Min Chul Suh5,Seung Yoon Ryu2,Han Woo2,Tae-Woo Lee1
Seoul National University1,Korea University2,Graphene Square3,Korea Basic Science Institute4,Kyung Hee University5
Huanyu Zhou1,Shin Jung Han1,Amit Kumar Harit2,Dong hyun Kim2,Dae Yoon Kim3,Yong Seok Choi3,Hyeokjun Kwon1,Kwan-Nyeong Kim1,Gyeong-Tak Go1,Hyung Joong Yun4,Byung Hee Hong3,Min Chul Suh5,Seung Yoon Ryu2,Han Woo2,Tae-Woo Lee1
Seoul National University1,Korea University2,Graphene Square3,Korea Basic Science Institute4,Kyung Hee University5
Intrinsically stretchable organic light-emitting diodes (ISOLEDs) are becoming essential components of wearable electronics. However, the efficiencies of the ISOLEDs have been highly inferior to their rigid counterparts, which is due to the lack of ideal stretchable electrode materials that can overcome the poor charge injection at one-dimensional metallic nanowire/organic interfaces. We demonstrate highly-efficient ISOLEDs that use two-dimensional-contact stretchable electrodes (TCSEs) that incorporate a graphene layer on top of embedded metallic nanowires. The graphene layer modifies the work function, promotes charge spreading, and impedes inward diffusion of oxygen and moisture. The work function (WF) of 3.63 eV is achieved by forming a strong interfacial dipole after deposition of a newly-designed conjugated polyelectrolyte with crown ether and anionic sulfonate groups on TCSE; this is the lowest value ever reported among ISOLEDs, which overcomes the existing problem of very poor electron injection in ISOLEDs. Subsequent pressure-controlled lamination yielded a highly efficient fluorescent ISOLED with an unprecedently high current efficiency of 20.3 cd/A, which even exceeds that of an otherwise-identical rigid counterpart. Lastly, a three-inch five-by-five passive matrix ISOLED was demonstrated using convex stretching. This work can provide a rational protocol for designing intrinsically stretchable high-efficiency optoelectronic devices with favorable interfacial electronic structures.<br/><br/><b>Reference</b><br/><i>Adv. Mater</i>. Accepted Author Manuscript 2203040. https://doi.org/10.1002/adma.202203040