Hard x-ray photoelectron spectroscopy study of Ge2Sb2Te5; as-deposited amorphous, crystalline, and laser-reamorphized

We have investigated the electronic structure of as-deposited, crystalline, and laser-reamorphized Ge2Sb2Te5 using high resolution, hard x-ray photoemission spectroscopy. A shift in the Fermi level as well as a broadening of the spectral features in the valence band and the Ge 3d level between the amorphous and crystalline state is observed. Upon amorphization, Ge 3d and Sb 4d spectra show a surprisingly small breaking of resonant bonds and changes in the bonding character as evidenced by the very similar density of states in all cases.