Dresden 2014 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 81: Poster: Energy materials incl. photovoltaics
HL 81.15: Poster
Wednesday, April 2, 2014, 17:00–20:00, P1
Electronic structure of Cu/In/Ga/Se-containing semiconductors — Juliana Srour1, Fouad El Haj Hassan1, •Andrei Postnikov2, Michael Yakushev3, and Tatyana Kuznetsova4 — 1Lebanese University, Beirut, Lebanon — 2University of Lorraine, Metz, France — 3Strathclyde University, Glasgow, UK — 4Institute of Metal Physics, Yekaterinburg, Russia
Semiconductors based on the chalcopyrite-type CuInSe2 (1-1-2) are promising for applications in photovoltaics, not least because their properties are not much deteriorated by the presence of typical point defects and deviations from stoichiometry. For tuning of electronic characteristics, indium is sometimes used in isoelectronic substitution by gallium. Such 1-1-2 compounds belong to a larger family of ternary phases, including notably 1-3-5 and 1-5-8 as particularly stable ones, which do often appear in practical synthesis. The structure of these phases can be generally derived from the zincblende one, with different substitutions on the cationic sublattice and a possible inclusion of ordered defects; however, some details of structures are still subject to debate. The 3-component region of the phase diagram, on its side of binary In-Se, borders to InSe (or, correspondingly, GaSe) semiconductors of not zincblende type (double-layer structure with cation-cation bonds). Different packing of layers gives rise to several polytypes. We study electronic structure of some representative binary and ternary compounds from first principles, using several flavours of exchange-correlation potentials, in order to test the impact of the latter on the band structure and on comparison with available experimental spectra.