title: Light harvesting improvement of organic solar cells with self-enhanced active layer designs.
abstract: We present designs of organic solar cells (OSCs) incorporating periodically arranged gradient type active layer. The designs can enhance light harvesting with patterned organic materials themselves (i.e. self-enhanced active layer design) to avoid degrading electrical performances of OSCs in contrast to introducing inorganic concentrators into OSC active layers such as silicon and metallic nanostructures. Geometry of the OSC is fully optimized by rigorously solving Maxwell's equations with fast and efficient scattering matrix method. Optical absorption is accessed by a volume integral of the active layer excluding the metallic absorption. Our numerical results show that the OSC with a self-enhanced active layer, compared with the conventional planar active layer configuration, has broadband and wide-angle range absorption enhancement due to better geometric impedance matching and prolonged optical path. This work provides a theoretical foundation and engineering reference for high performance OSC designs.
authors.affiliation: Department of Electrical and Electronic Engineering, the University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Luzhou
authors.initials: L
authors.lastname: Chen
authors.forename: Wei E I
authors.initials: WE
authors.lastname: Sha
authors.forename: Wallace C H
authors.initials: WC
authors.lastname: Choy
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D011211:Electric Power Supplies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D008962:Models, Theoretical; D055096:Optical Devices; D009930:Organic Chemicals / Q000737:chemistry*; D012542:Scattering, Radiation; D012993:Solar Energy
chemical_list: D009930:Organic Chemicals