Material development for intrinsically stretchable organic solar cells

Abstract

Recently, development of stretchable OSCs, which are regarded as the next generation of flexible electronic devices, has emerged as interesting topics. In particular, OSCs have been expected to be used as wearable devices that can be attached to the body due to their lightness, superior flexibility, and stretchability. In order to realize the intrinsically stretchable OSCs, all components of the OSCs, including the electron/hole transporting layers, substrates, electrodes, and active layer, must to be changed to stretchable materials. Also, it is important to improve the adhesive between the layers and the cohesive energy. So far, the intrinsically stretchable OSCs has not been studied yet due to its technical limitations. Here, in this study, using stretchable conductive polymer electrodes(PEDOT:PSS) along with TPU substrate replacing metal based ITO/Glass, complete stretchable OSCs was intrinsically realized. Especially, highly efficient PM6:Y6 photovoltaic blend system showed PCE of over 9%, which is the highest efficiency over the world in this field. Furthermore, the mechanism of crack generation by deformation of stretchable OSCs was analyzed using tensile test and in-situ SEM. These studies suggest important guidelines for optimization of stretchable substrates and intrinsically sustainable stretchable devices.