engleski

Exponential absorption edge and implantation-induced modifications in amorphous gallium arsenide

Implantation induced microstructural modifications have been measured in amorphous GaAs using Raman scattering spectroscopy and optical absorption in the sub-gap region. Additional evidence is given that the amorphous phase consists of two components, which continuously evolve as a function of ion dose. A characteristic disorder-related Urbach parameter from the absorption measurements was used as a measure of the total disorder at each dose, whereas Raman results enabled the separation of a random (a-CRN) and a medium range ordered (a-BP) component of amorphous network. As the dose is increased, the a-CRN fraction gradually converts into the a-BP fraction. The decrease of the remaining a-CRN fraction with dose correlates with the decrease of the disorder as observed by absorption measurements and Urbach parameter.

GaAs; implantation; absorption edge; Urbach edge

nije evidentirano