Density of Upper Valence Band States of Amorphous Arsenic Selenide System Determined by Ultraviolet Photoelectric Emission Spectroscopy

抄録

The density of upper valence band states (U-DOVS) of amorphous As_xSe_100−x in the compositional region of 0≤x≤50 was investigated with ultraviolet photoelectric emission spectroscopy. The U-DOVSs in the regions of 0≤x≤40 and 40≤x≤50 are well described by U-DOVSs synthesized from those of properly weighted Se and As₂Se₃, and As₂Se₃ and As₄Se₄, respectively. These facts show that the hetero-bonding is predominant compared with the homo-bonding, and the dominant structure of U-DOVS is determined from the structure of the first nearest neighbour atoms.