title: Analysis of SnS2 hyperdoped with V proposed as efficient absorber material.
abstract: Intermediate-band materials can improve the photovoltaic efficiency of solar cells through the absorption of two subband-gap photons that allow extra electron-hole pair formations. Previous theoretical and experimental findings support the proposal that the layered SnS2 compound, with a band-gap of around 2 eV, is a candidate for an intermediate-band material when it is doped with a specific transition-metal. In this work we characterize vanadium doped SnS2 using density functional theory at the dilution level experimentally found and including a dispersion correction combined with the site-occupancy-disorder method. In order to analyze the electronic characteristics that depend on geometry, two SnS2 polytypes partially substituted with vanadium in symmetry-adapted non-equivalent configurations were studied. In addition the magnetic configurations of vanadium in a SnS2 2H-polytype and its comparison with a 4H-polytype were also characterized. We demonstrate that a narrow intermediate-band is formed, when these dopant atoms are located in different layers. Our theoretical predictions confirm the recent experimental findings in which a paramagnetic intermediate-band material in a SnS2 2H-polytype with 10% vanadium concentration is obtained.
authors.affiliation: Instituto de Energía Solar, Universidad Politécnica de Madrid UPM, Ciudad Universitaria, 28040 Madrid, Spain. Department of TEAT, ETSI Telecomunicación, UPM, Ciudad Universitaria. 28040 Madrid, Spain.
authors.forename: Yohanna
authors.initials: Y
authors.lastname: Seminovski
authors.forename: Pablo
authors.initials: P
authors.lastname: Palacios
authors.forename: Perla
authors.initials: P
authors.lastname: Wahnón