Investigation of surface passivation of amorphous silicon using photothermal deflection spectroscopy

Abstract
We have used photothermal deflection spectroscopy to examine optical absorption in amorphous silicon films using a variety of surface passivation techniques. Absorption coefficients well below the band gap in these films are strongly influenced by surface state densities. Surfaces oxidized by either chemical treatment or in oxygen-containing plasmas show lower interface state densities than do those passivated with deposited dielectrics.