Schottkyhyphen;barrier ellipsometric electroreflectance in GaAs

摘要

A theory and an experimental method of Schottkyhyphen;barrier ellipsometric electroreflectance (or electrichyphen;fieldhyphen;modulated ellipsometry) at sufficiently low fields are presented. The real part and the imaginary part of fieldhyphen;induced changes in the dielectric function of GaAs in the vicinity of theE1transition have been determined, independently and simultaneously, by the present theory without use of the Kramershyphen;Kronig relation. Spectra obtained are analyzed by the lowhyphen;field electroreflectance theory. Resulting energyhyphen;band parameters are as follows: the energy band gapEg=2.928plusmn;0.003 eV and the broadening energy Ggr;=57plusmn;2 meV for theE1transition (M1type), andEg=3.152plusmn;0.003 eV and Ggr;=78plusmn;3 meV for theE1+Dgr;1transition (M1type) at room temperature. Effects of linear electroreflectance upon the present Schottkyhyphen;barrier ellipsometric electroreflectance spectra have been discussed.