Optical absorption and refraction spectra in highly excited GaSb

A theoretical estimate of carrier-induced changes in absorption and refraction spectra in GaSb is presented. The partly phenomenological electron-hole plasma model including band filling, band-gap renormalization, screening of the Coulomb interaction and the free-carrier plasma effect is used. A dominant contribution of the band filling and screening of the continuum-state Coulomb enhancement is observed. For the first time the influence of high lying conduction band valleys is taken into account. In addition, the model is applied to calculate the absorption and refraction spectra in doped material. The obtained results may prove to be useful in the design of GaSb optoelectronic devices.<
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