Passivation of threading dislocations in an incommensurate Ge0.36Si0.64/Si structure is studied using hydrogen plasma anneal. The reverse current ofpnjunction diodes made of the above structure is reduced by more than 30 times after hydrogenation. Associated improvements in the current‐voltage (I‐V) characteristics is also observed. Capacitance‐voltage (C‐V) measurements reveal that the shallow dopants neutralized by hydrogenation reactivate at lower temperatures than the passivated deep level defects. Secondary‐ion mass spectroscopy (SIMS) analysis established the depth of diffusion of hydrogen under the experimental conditions. Work in this direction could eventually lead to the integration of infrared detectors with Si very large scale integration (VLSI).