The formation of p-n junctions in Hg1-xCdxTe is still an open research task. In this paper, laser treatment of n-type Ha(1-x)Cd(x)Te samples resulting in the formation of a p-n junction is studied. The YAG:Nd3+ laser with pulse duration of 250 mu s or 40 ns was used. The energy density of laser beam was below the threshold of sample surface melting. The interpretation of the results is based on a model of defects formation related to interstitial mercury diffusion following laser irradiation. The Hall measurements clearly point out to a simple p-n junction. The resistance of samples shows the long time relaxation described by the 1/2 power law, which is attributable to the defect diffusion processes, but not to the changes in the electron-hole systems. (c) 2005 Elsevier B.V. All rights reserved.