Charge transfer complexes in intercalated layer compounds

Abstract

The properties of intercalated transition element dichalcogenides are examined using the Mulliken concept of charge transfer complexes. Different behaviour is found for compounds of Groups IVB, VB and VIB of the Periodic Table. The observed shifts are bathochromic for the IVB and VB but hypsochromic for 2H-MoS₂ intercalated compounds. Only one or two optical transitions are affected and these depend on the intercalated molecule. Some evidence is given for the presence of charge transfer bands in intercalated 2H-MoS₂ and 1T-HfS₂. The importance of the symmetry and ionization potentials of the energy levels in the interacting compounds is discussed.