High -temperature recharging of deep centers and disorder effects in GaAs doped with chromium

At room temperature , the laws of photosensitivity (PS) change of GaAs (Cr) crystals by spectral and integral bias lighting are investigated. Nonreproducibility of the spectral photoresponse i$_M$ at the intrinsic-PS maximum is found. Since the time relaxation p$_T$(t), μ$_nT$(t) after illumination in the region of the impurity quenching effect (QE) occurs in a matter of days , it may be concluded that deep donors play an important role in the formation of GaAs (Cr) PS and also that compensational inhomogeneity associated with strong filling of the working levels by electrons is present in n samples. It is shown that stimulation effects may be due to liquidation of the inhomogeneity by the illumination, even such as to cause QE by predominant hole generation at larger I.