The Role of Device Architecture and Interfacial Layer on Performance of Semitransparent Organic Solar Cells

Semitransparent organic solar cells (ST‐OSCs) generally suffer from voltage loss in comparison to their opaque counterparts. Herein, ST‐OSCs constructed with conventional and inverted structures have been explored. The voltage losses of the inverted ST‐OSCs are lower than that of the conventional architectures when the thicknesses of the top transparent electrodes approach the percolation threshold, which is attributed to the larger surface energy of the bottom seeding layers, higher built‐in electric fields, and lower recombination losses. Moreover, ST‐OSCs with conventional architectures based on four commonly used electrode transporting layers (ETLs) PDINN, PDINO, PNDIT‐F3N, and PFN‐Br are employed to distinguish the V oc variation when capping with 10 nm top electrodes. It is revealed that ETL with larger surface energy and a stronger ability to reduce the cathode work function is more beneficial for reducing the voltage loss for ST‐OSCs. This work demonstrates the crucial role of device structure and interfacial layers in optimizing the ST‐OSC device performance.