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Band Structure of Layer Crystals NbSe 2 and MoS 2 and an Interpretation of Their Optical Spectra
Author(s) -
Leveque G.,
RobinKandare S.,
Martin L.
Publication year - 1974
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.2220630232
Subject(s) - conduction band , spectral line , valence (chemistry) , electronic band structure , condensed matter physics , density of states , valence band , reflectivity , chemistry , thermal conduction , atomic physics , materials science , optics , band gap , physics , quantum mechanics , organic chemistry , composite material , electron
The optical functions a and ε 2 ω 2 of NbSe 2 and MoS 2 are deduced from reflectivity measurements between 2 and 70 eV. Basing on the results of photoemission studies and band structure calculations, an experimental model is proposed of the density of states for both the valence and conduction bands. As expected, the optical behaviours of NbSe 2 and MoS 2 are very similar. The shape of the ε; 2 ω 2 curve in the high energy range (30 to 50 eV) corresponding to deep level excitations describes the density of states of the conduction band in spite of some broadening of the structure. This broadening is not of experimental origin.