(A) study on interfacial adhesion control to improve the mechanical stability of stretchable devices

Abstract

Stretchable organic solar cells (SOSCs) have been attracting paramount attention due to the increasing demand for off-grid power sources for wearable electronics. Since conventional solar cells contain brittle materials such as oxides and rigid metal electrodes, cracks easily generate and propagate under mild tensile strain. To overcome this issue, intrinsically SOSCs, which have stretchability on all layers, have been reported. However, the stretchability of these SOSCs is still insufficient to be applied to wearable devices which have to accommodate the strain of more than 40%. Moreover, under the tensile strain, the degradation mechanisms of SOSCs have scarcely been studied. In this work, by revealing the fact that PEDOT:PSS, a widely used material as an electrode of optoelectronics, is a crack-initiating layer, we successfully improved the stretchability of SOSCs through the control of interfacial adhesion between the substrate and PEDOT:PSS. Furthermore, the effect of cracks on devices was investigated through changes in parameters and PCE in tensile conditions.