Structural chemical states of dopant atoms of platinum and gold in glass-like arsenic selenides

Resumo

Dopant atoms of platinum do not change the parameters of electric conductivity and optical band gap width of glass-like arsenic selenides, they are stabilized as ions Pt²⁺ and Pt⁴⁺ with different local environment symmetries, and the ratio of their concentration depends on the composition of glass and the speed of melt solidification process during its production. It is assumed that platinum forms amphoteric two-electron centers with negative correlation energy in a glassy network. Dopant atoms of gold decrease the energy of electric conductivity activation and the optical band gap width of glass-like arsenic selenides and form a compound of trivalent gold with arsenic and selenium in the glassy network. The decrease of the band gap width of glass doped with gold is associated with the formation of solid solutions in the glass, which include a narrow-bandgap semiconducting gold compound.