Laser-induced dewetting of As₂₀Se₈₀ thin films

We have studied photo-induced (PI) dewetting of thin amorphous chalcogenide films (ACF) As₂₀Se₈₀ that occurs on glass substrates under continuous wave (cw) laser illumination (λ = 660 nm). The kinetics of PI growth of pores has been studied both experimentally and theoretically. Experiments were carried out with films of various thicknesses (50–700 nm) in the temperature range 273–393 K. The nucleation of pores under illumination is accelerated by the formation of ripples on the surface of ACF. A model of PI dewetting that occurs by volume diffusion of the film constituents driven by capillary forces is developed. According to the model, the pore radius grows with time as t¹/² that is confirmed in our experiments. The PI diffusion coefficients, which are determined from the dewetting kinetics, are in good agreement with previous experimental and theoretical results.