Enhancement in Photocurrent through Efficient Geometrical Light Trapping in Organic Photovoltaics

摘要

Geometrical light trapping is a simple and promising strategy to substantially improve the optical absorption and efficiency of solar cells. Nonetheless, implementation of geometrical light trapping in organic photovoltaics is challenging due to the fact that a uniform organic active layer can rarely be achieved on textured substrates. In this work, geometrical light trapping is achieved by introducing a randomly nanostructured front electrode, which enhances the performance in organic photovoltaics. A uniform and conformal active layer exhibiting the morphology of the nanostructured electrode is realized, which guarantees high open-circuit voltage and fill factor. Efficient geometrical light trapping leads to enhanced light absorption in the active layer, which results in an enhanced short-circuit current density. Compared with the reference device with a flat electrode, the device utilizing a geometrical light-trapping electrode can yield an additional 1-2 mA cm(-2) increase in photocurrent.