Photoluminescence (PC) measurements of the GaMnAs layers embedded with MnAs clusters have been performed. It was shown that the presence of MnAs clusters in the semiconducting matrix leads to appearance in the PL spectra a broad peak with local maximums at 1.36 and 1.33 eV. which are related with the defects generated in the phase separation process. The effect of the MnAs clusters on the temperature dependent band gap of GaMnAs was also observed. (c) 2005 Elsevier B.V. All rights reserved.