"Effects of thermal annealing on optical absorption of amorphous indium selenide thin films"

The thermal annealing behaviour of optical absorption in amorphous indium selenide thin films is investigated in the visible spectral range. Annealing is performed at different temperatures and for different periods of time. In all the examined cases it is found that the dependence of the absorption coefficient α on the photon energy h{stroke}ω is well described by the relation α h {combining short stroke overlay}ω = B( h {combining short stroke overlay}ω - Eopt)2. The increase in the values of the optical gap Eopt for samples annealed between 300 and 550 K is ascribed to the decrease of the unsaturated bonds in the amorphous structure due to heat treatment.