Aminosilane as a Molecular Linker between the Electron-Transport Layer and Active Layer for Efficient Inverted Polymer Solar Cells

Interfacial modification is crucial for improving the photovoltaic performance. In this work, we present an aminosilane as a molecular linker between the ZnO electron-transport layer and fullerene derivative phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM)-based active layer for efficient inverted polymer solar cells. An enhancement in the power-conversion efficiency (PCE), from 8.47 to 9.46%, was achieved on using PTB7-Th as donors. The aminosilane molecular linker provides dual functionalities for enhanced PCE, including (1) passivating the ZnO surface and decreasing the surface work function of ZnO for energy-level alignment and (2) bonding onto the fullerene derivative PC₇₁BM-based active layer to reduce the interface contact resistance.