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Optical Spectra and Band Structure of As 2 Se 3
Author(s) -
Althaus H. L.,
Weiser G.,
Nagel S.
Publication year - 1978
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220870114
Subject(s) - stacking , spectral line , polarization (electrochemistry) , band gap , lone pair , molecular physics , electronic band structure , valence band , condensed matter physics , valence (chemistry) , materials science , chemistry , physics , molecule , organic chemistry , astronomy
The optical properties of the layer material As 2 Se 3 at low temperature are presented in the energy range between 1 and 9 eV for polarization of light parallel to the three crystal axes including the stacking direction of the layers. The results are compared with a band structure calculated by means of a semi‐empirical tight‐binding model. It turns out that in As 2 Se 3 no lone‐pair bands exist like for instance in Se. In particular there is no gap between bonding and non bonding p states. The direct gap occurs at the point Γ. Some of the upper valence bands near Γ show considerable splitting due to interlayer interaction. Nevertheless selection rules and the dependence of the optical spectra on the polarization of light are essentially determined by the symmetry of the single layer.