Ion-beam-synthesized beta-FeSi2/Si interfaces were investigated by carrier-injection photo luminescence (CPL) measurements. The CPL intensity of Al-doped beta-FeSi2/Si sample was larger than that of non-doped one. We obtained a carrier injection efficiency (7) of gamma = 0.41 in the M-doped sample and y = 0.19 in the non-doped one. These results revealed that Al-doping into beta-FeSi2 is an effective technique for the improvement of beta-FeSi2/Si interface which is defective due to ion implantation damages. (c) 2007 Elsevier B.V. All rights reserved.