Soft x-ray induced Ag diffusion in amorphous pulse laser deposited As50Se50 thin films: An x-ray photoelectron and secondary ion mass spectroscopy study

Abstract

Photoinduced interdiffusion in nanolayered Se ∕ As 2 S 3 films: Optical and x-ray photoelectron spectroscopic studies J. Appl. Phys. 99, 094301 (2006); 10.1063/1.2193061 X-ray photoelectron spectroscopic investigation of surface chemistry of ternary As-S-Se chalcogenide glasses Refractive index change caused by electron irradiation in amorphous As-S and As-Se thin films coated with different metalsIn the present paper, x-ray photoelectron spectroscopy ͑XPS͒ is used to induce and study the Ag diffusion and dissolution in pulsed laser deposited As 50 Se 50 amorphous chalcogenide films. Dynamic secondary ion mass spectroscopy ͑SIMS͒ is also employed to investigate the Ag atomic concentration in depth. Dynamic SIMS measurements reveal that even before x-ray irradiation a considerable percentage of the total silver amount diffuses into the matrix forming an ϳ70 nm mixed Ag-Se-As layer. XPS analysis shows that x-ray irradiation induces further diffusion of silver into the chalcogenide matrix. At the end of the procedure silver is found to be homogeneously dissolved into the matrix leaving only a 5-7 nm thick surface layer with excess silver concentration. In this surface layer stable Ag 2 Se clusters existing probably in quasicrystalline form prohibit further diffusion. The origin of the mechanism of the x-ray induced Ag diffusion and dissolution in amorphous chalcogenides is discussed in light of the present results.

Ag diffusion in amorphous As50Se50 films studied by XPS

“…2(a). This peak is attributed to Se atoms that participate in intermediate Ag-Se-As-Se-Ag species (hereafter referred to as As-Se-Ag species) [16]. The justification of this interpretation originates from the fact that the electronic density around Se atoms in these species should increase due to electron transfer from neighboring Ag atoms causing the observed chemical shift of the Se3d spectrum at lower binding energies.…”

Athermal Photoelectronic Effects in Non-Crystalline Chalcogenides: Current Status and Beyond

“…Arsenic-rich, binary As-Se amorphous films grown by the pulsed-laser deposition technique were shown, using x-ray photoelectron spectroscopy (XPS), to exhibit strong nanoscale phase separation [110,111]. This particular deposition Athermal photoelectronic effects in non-crystalline chalcogenides: Current status and beyond 35 method plays significant in the growth of amorphous chalcogenides with tailoredmade functionalities owing to its advantage of maintaining quite well the composition of the target material, avoiding also the formation of structures and morphologies associated with irreversible processes.…”