Wu, M.-C.M.-C.WuChan, S.-H.S.-H.ChanLee, K.-M.K.-M.LeeChen, S.-H.S.-H.ChenJao, M.-H.M.-H.JaoChen, Y.-F.Y.-F.ChenYANG-FANG CHENWEI-FANG SU2020-05-122020-05-122018https://scholars.lib.ntu.edu.tw/handle/123456789/492108Lead halide perovskite-structured solar cells (PSCs) have drawn great attention due to a rapid improvement in their photoelectric conversion efficiency in recent years. In this study, we have enhanced photovoltaic performance by using mesoscopic zinc-doped TiO2 (meso-Zn:TiO2) as the electron extraction layer. Zn:TiO2 nanoparticles (Zn:TiO2 NPs) with various zinc doping levels were synthesized by combining sol-gel and hydrothermal methods. The synthesized Zn:TiO2 NPs were used to fabricate electron extraction layers by a screen-printing method. We systematically investigated the surface morphology, crystal structure, contact angle, charge carrier dynamics, electron mobility, and electrical conductivity of various meso-Zn:TiO2. Furthermore, photo-assisted Kelvin probe force microscopy (KPFM) was used to analyze the surface potential of perovskite films coated with various meso-Zn:TiO2 to understand the electron extraction behavior under the illumination of light at various wavelengths. Moreover, the energy levels of various meso-Zn:TiO2 were estimated by ultraviolet photoelectron spectroscopy (UPS) and UV-vis absorption spectroscopy. We discovered that the 5.0 mol% meso-Zn:TiO2 exhibited the optimal band alignment with perovskite. Finally, the average power conversion efficiency (PCE) of PSCs with meso-Zn:TiO2 was enhanced from 13.1 to 16.8%, and such fabricated PSC yielded a champion PCE of 18.3%. © 2018 The Royal Society of Chemistry.[SDGs]SDG7Absorption spectroscopy; Contact angle; Conversion efficiency; Crystal structure; Electrons; Extraction; Lead compounds; Perovskite; Perovskite solar cells; Photoelectricity; Screen printing; Semiconductor doping; Sol-gels; Solar cells; Superconducting materials; Surface potential; Synthesis (chemical); Titanium dioxide; Ultraviolet photoelectron spectroscopy; Ultraviolet spectroscopy; Uninterruptible power systems; Charge carrier dynamics; Electrical conductivity; Hydrothermal methods; Kelvin probe force microscopy; Photo-electric conversion efficiency; Photovoltaic performance; Screen printing methods; UV-Vis absorption spectroscopy; Zinc compoundsjournal article10.1039/c8ta05291c2-s2.0-85053524906https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053524906&doi=10.1039%2fc8ta05291c&partnerID=40&md5=e0806aa8ef7915ff03b164d7acf00424