posted on 2020-03-12, 14:05authored byTheodore
D. C. Hobson, Laurie J. Phillips, Oliver S. Hutter, Huw Shiel, Jack E. N. Swallow, Christopher N. Savory, Pabitra K. Nayak, Silvia Mariotti, Bhaskar Das, Leon Bowen, Leanne A. H. Jones, Thomas J. Featherstone, Matthew J. Smiles, Mark A. Farnworth, Guillaume Zoppi, Pardeep K. Thakur, Tien-Lin Lee, Henry J. Snaith, Chris Leighton, David O. Scanlon, Vinod R. Dhanak, Ken Durose, Tim D. Veal, Jonathan D. Major
The
carrier-type of the emerging photovoltaic Sb2Se3 was evaluated for both thin films and bulk crystals via a
range of complementary techniques. X-ray photoelectron spectroscopy
(XPS), hot probe, Hall effect, and surface photovoltage spectroscopy
showed films and crystals synthesized from the Sb2Se3 granulate material to be n-type with chlorine identified
as an unintentional n-type dopant via secondary ion mass spectrometry
analysis. The validity of chlorine as a dopant was confirmed by the
synthesis of intrinsic crystals from metallic precursors and subsequent
deliberate n-type doping by the addition of MgCl2. Chlorine
was also shown to be a substitutional n-type shallow dopant by density
functional theory calculations. TiO2/Sb2Se3 n–n isotype heterojunction solar cells with 7.3% efficiency
are subsequently demonstrated, with band alignment analyzed via XPS.