INVERSE-PHOTOEMISSION SPECTROSCOPY OF GASE AND INSE

The lamellar semiconductors GaSe and InSe have been studied with k-res olved inverse-photoemission spectroscopy along two major symmetry dire ctions (GAMMABAR KBAR and GAMMABAR MBAR) of the surface Brillouin zone . Three bands with well-resolved features are observed from which the dispersion of the conduction bands can be determined with good precisi on. The minimum of the conduction band is found at MBAR in GaSe and at GAMMABAR in InSe. These results are compared with theoretical studies using pseudopotential and tight-binding calculations.