Optical absorption behaviour of magnesium-implanted GaAs

Optical absorption spectra of magnesium implanted GaAs single crystals are measured in the photon energy range below the fundamental absorption edge. It is found that the absorption coefficient increases with increasing fluence up to a saturation value of about 5 · 104 ⁴ cm⁻¹ at 1.36 eV. The results are compared with optical measurements on GaAs single crystals implanted with other ions.