The ohmic contact formation mechanism in pulsed laser beam mixed Au/Te/Au/GaAs structures has been investigated by129I Mo¨ssbauer spectroscopy. Low‐resistance, ohmic contact structures, on bothn‐ andp‐type GaAs, were found to be correlated to the formation of a high density of defect complexes consisting of tellurium atoms quasi‐substitutional on arsenic sites with a gallium vacancy in the first neighbor shell. Correspondingly, the ohmic conduction is suggested to occur according to the amorphous heterojunction model, i.e., by a multi‐step recombination‐tunneling process.