In‐vacancies in Si‐doped InN

Abstract

Abstract The introduction of vacancy type point defects by Si doping in InN grown by plasma‐assisted molecular beam epitaxy was studied using a monoenergetic positron beam. With the combination of positron lifetime and Doppler broadening measurements, compensating In‐vacancy ( V In ) acceptors were identified in the material. For increasing Si doping an enhanced formation of V In defects was observed, up to a concentration of $c_{\rm V} = 7 \times 10^{17} \,{\rm cm}^{ - 3} $ in the highest doped sample ( $n_{\rm e} = 6.6 \times 10^{20} \,{\rm cm}^{ - 3} $ ). A strong inhomogeneity of the defect profile with a significant increase of the V In concentration toward the layer/substrate interface could be detected. Additionally, larger vacancy clusters containing several V In are formed in the proximity of the interface.