Interface-mediated suppression of radiation damage in GaN

Interfaces are often sinks for radiation-generated defects and could either promote defect recombination or cause detrimental disorder accumulation. Here, we study (0 0 0 1) GaN irradiated with 500 keV Xe ions at room temperature. Results show that, when point defects are generated within ∼50 nm from the surface, they experience efficient recombination without any measurable increase in the rate of surface amorphization. Our findings provide clear experimental evidence of efficient suppression of radiation damage by an interface in a non-metallic material.