Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 81: Electronic Structure Theory: Many-Body Effects (organized by O)

TT 81.9: Poster

Mittwoch, 18. März 2015, 18:15–21:00, Poster A

Size-dependent optical gaps of Cu chalcogenide nanocrystals from GW and the Bethe-Salpeter equation — •Sabine Körbel^1,2, Miguel Alexandre Lopes Marques^1,2,3, and Silvana Botti^4,2,3 — ¹Martin-Luther-Universität Halle-Wittenberg, Germany — ²Université Claude Bernard Lyon 1, France — ³European Theoretical Spectroscopy Facility — ⁴Friedrich-Schiller-Universität Jena, Germany

In semiconductor nanocrystals, quantum confinement, which opens the optical gap with decreasing nanocrystal size, allows to tune the optical absorption edge. Hence, nanoparticles of different sizes may be used in multilayer thin-film solar cells, with each layer consisting of nanocrystals of a different size, absorbing light at a different frequency, therefore enhancing the overall efficiency of the solar cell, all the while using one and the same photovoltaic absorber material. Here we present size-dependent optical gaps of nanocrystals of Cu₂ZnSn(S,Se)₄ [CZTS(e)], an earth-abundant semiconductor with a direct optical gap suitable for solar-cell absorbers, calculated with GW and the Bethe-Salpeter equation, and compared to experimental data, where available.