Study of Photo-Induced Effect in Obliquely-Deposited Amorphous Ge-Se Films by XPS

Abstract
Amorphous GeSe, GeSe2 and GeSe3 films were investigated by XPS. Binding energies and chemical shifts of the 3d and 3p electrons of the constituent elements were measured. It was found that obliquely-deposited GeSe3 films contain four(Ge)-two(Se) fold and three(Ge)-three(Se) fold bondings, while normally-deposited films have the former type bonding alone. Photo-induced chemical shifts of obliquely-deposited GeSe3 films are attributable to a transformation from the four(Ge)-two(Se) fold bonds to the three(Ge)-three(Se) bonds. The mechanism of thephoto-induced effect is described.