The ‘‘electroless’’ deposition method of Au thin films onn‐type ZnCdTe crystal surfaces has been investigated by atomic force microscopy, x‐ray photoelectron spectroscopy, and low temperature photoluminescence. The blocking contact behavior of these films was strongly dependent on post deposition annealing treatments which were also found to induce modifications in the surface morphology and surface chemical composition. Heat treatments (at 300 °C) in vacuum eliminates most of the interfacial tellurium oxide introduced during the deposition. Annealing also reduces the radiative recombination at defects in the region below the interface and increases the barrier height of the contact. ©1995 American Institute of Physics.