Transmission spectra of some transition metal dichalcogenides. I. Group IVA: octahedral coordination

Abstract

The transmission spectra of the layer type group IVA transition metal dichalcogenides have been measured at liquid helium temperature. A great deal more fine structure has been found in these spectra than in those of earlier work, due to interband transitions which have not been observed previously. In all the spectra there is a broad high absorption region and the authors have tried to explain the trend this follows from compound to compound in terms of the known composition of the valence and conduction bands in these materials. There is generally a good agreement between the energies of the interband transitions observed and those of the band structures for these materials.