Photoinduced phenomena in As4Se3 amorphous thin films prepared by pulsed laser deposition

Pulsed laser deposition technique was employed for the preparation of amorphous As4Se3 thin films. Raman scattering spectroscopy and variable angle spectroscopic ellipsometry results revealed reversible photostructural effects and metastable photorefraction in annealed films. Observed photoinduced effects are ascribed to reversible transformation of As4, As4Se3, and As4Se4 structural units to AsSe3, As2Se2 and As3Se entities.