Structural And Electronic Rearrangement In Ovonic Switching Gexse1-X(0,4 <= X <= 0,72) Films

Nature of gap states in chalcogenide semiconductors GexSe1-x is studied by combining X-ray photoelectron (XPS) and absorption (NEXAFS) spectroscopy with photoconductivity (PC) and internal photoemission (IPE) measurements at the semiconductor/insulator interface. It is shown that studied GexSe1-x layers are heterogeneous composite-like matrices and the gap states determining electron transport originate from formation of homopolar Ge-Ge bonds. Nanoscale phase separation effect is revealed manifesting in redistribution of GeSe2 and GeSe networks, respectively, with increase of Ge content with predominant contribution of GeSe.