Antireflective, self-cleaning and protective film by continuous sputtering of a plasma polymer on inorganic multilayer for perovskite solar cells application

Abstract

Optical films with antireflective and self-cleaning surfaces have much potential for applications in solar cells, architectural glasses, and outdoor displays. Here we demonstrate the fabrication of novel self-cleaning antireflection (AR) thin films by depositing plasma-polymerized fluorocarbon (PPFC) which is fluorinated polymer consisting carbon and fluorine formed under plasma environment on Nb2O5/SiO2/Nb2O5 (NSN) trilayers using mid-range frequency power source in a continuous roll-to-roll sputtering system. The reflectance of PPFC/NSN films with a PPFC thickness of 70 nm was 1.71% at a wavelength of 528 nm, and the PPFC/NSN films showed low reflectance in a wide range in the visible region. The PPFC/NSN AR films exhibited a water-repelling surface with water contact angle of 105° after the application of a top fluorocarbon layer with low surface energy. We tested and confirmed the AR and self-cleaning functions of the PPFC/NSN films through the incorporation to perovskite solar cells (PSC). The short-circuit current density and power conversion efficiency of PPFC/NSN/HC-PET/PSC were 20.6 mA cm−2 and 17%. By attaching a self-cleaning AR films to both side of PSC, photocurrent collection of the device was improved and applicability of protective films to PSC was demonstrated.