Understanding the metal-electrode-correlated degradation of organic solar cells under illumination/thermal stress

One of the main challenges limiting the commercialization of organic solar cells (OSCs) is the instability problem. Besides the active materials, the electrode especially metal electrode correlated degradation could mainly account for the efficiency decay of a device under illumination and/or thermal stress. However, this has often been neglected compared to the active layer. An in-depth and comprehensive understanding of the electrode-correlated degradation of OSCs is essential to conquer the instability challenge of OSCs. In this work, the detailed degradation of metal electrodes under light illumination and thermal stresses is systematically studied, by probing the morphological and chemical changes. According to the in-depth analyses, a degrading mechanism is proposed for the metal-electrode-correlated degradation of OSCs, which should be taken into account for further stability investigation and the industrial production of OSCs.