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Publication - Professor David Fermin

    Photovoltaic Performance of Phase-Pure Orthorhombic BiSI Thin-Films


    Tiwari, D, Alibhai, D, Delgado, FC, Mombru, M & Fermin, D, 2019, ‘Photovoltaic Performance of Phase-Pure Orthorhombic BiSI Thin-Films’. ACS Applied Energy Materials, vol 2., pp. 3878-3885


    A single-precursor solution approach is developed for depositing stoichiometric BiSI thin films featuring pure paraelectric orthorhombic (Pnam) phase. The compact and homogeneous films are composed of flake-shaped grains oriented antiplanar to the substrate and display a sharp optical transition corresponding to a bandgap of 1.57 eV. Optical and Raman signatures of the thin films are rationalized using the quasiparticle G
    0@PBE0 and density functional perturbation theory calculations. Electrochemical impedance spectroscopy revealed n-type doping with valence and conduction band edges located at 4.6 and 6.2 eV below vacuum level, respectively. Planar BiSI solar cells are fabricated with the architecture: Glass/FTO/SnO
    2/BiSI/F8/Au, where F8 is poly(9,9-di-n-octylfluorenyl-2,7-diyl), showing record conversion efficiency of 1.32% under AM 1.5 illumination.

    Full details in the University publications repository