Breaking the Space Charge Limit in Organic Solar Cells by a Novel Plasmonic-Electrical Concept

Abstract

As a fundamental electrostatic limit, the space charge limit (SCL) for photocurrent is a universal feature and of paramount importance in organic semiconductors with unbalanced electron/hole mobility and high exciton generation. Here, we propose a new concept of plasmonic-electrical effect to manipulate the electrical properties (photocarrier generation, recombination, transport, and collection) of semiconductor devices with the help of plasmonically induced light redistribution. As a proof-of-concept, organic solar cells (OSCs) incorporating metallic planar and grating anodes are systematically investigated for normal and inverted device structures. Interestingly, although strong plasmonic resonances induce abnormally dense photocarriers around a grating anode, the grating-inverted OSC is exempt from space charge accumulation