title: Wavelength-Scale Structures as Extremely High Haze Films for Efficient Polymer Solar Cells.
abstract: Wavelength-scale inverted pyramid structures with low reflectance and excellent haze have been designed for application to polymer solar cells (PSCs). The wavelength-scale structured haze films are fabricated on the back surface of glass without damages to organic active layer by using a soft lithographic technique with etched GaN molds. With a rigorous coupled-wave analysis of optical modeling, we find the shift of resonance peaks with the increase of pattern's diameter. Wavelength-scale structures could provide the number of resonances at the long wavelength spectrum (λ = 650-800 nm), yielding enhancement of power conversion efficiency (PCE) in the PSCs. Compared with a flat device (PCE = 7.12%, Jsc = 15.6 mA/cm(2)), improved PCE of 8.41% is achieved in a haze film, which is mainly due to the increased short circuit current density (Jsc) of 17.5 mA/cm(2). Hence, it opens up exciting opportunities for a variety of PSCs with wavelength-scale structures to further improve performance, simplify complicated process, and reduce costs.
authors.affiliation: Department of Materials Science and Engineering, Division of Advanced Materials Science Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea.
authors.forename: Juyoung
authors.initials: J
authors.lastname: Ham
authors.affiliation: Department of Materials Science and Engineering, Division of Advanced Materials Science Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea.
authors.forename: Wan Jae
authors.initials: WJ
authors.lastname: Dong
authors.affiliation: Department of Materials Science and Engineering, Division of Advanced Materials Science Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea.
authors.forename: Gwan Ho
authors.initials: GH
authors.lastname: Jung
authors.affiliation: Department of Materials Science and Engineering, Division of Advanced Materials Science Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea.
authors.forename: Jong-Lam
authors.initials: JL
authors.lastname: Lee
keywords: antireflection coatings; haze films; polymer solar cells; wavelength-scale structure