Fe-doped InN layers grown by molecular beam epitaxy

Fe-doped InN have been grown by molecular-beam-epitaxy. It is found that Fe-doping leads to drastic increase of residual electron concentration, which is different from semi-insulating property of Fe-doped GaN. However, this heavy n-type doping can't be fully explained by Fe-concentration. Further analysis shows that more unintentionally-doped impurities such as hydrogen and oxygen are incorporated with increasing [Fe] and surface is degraded with high density pits, which probably are the main reasons for electron generation and mobility reduction. Photoluminescence of InN is gradually quenched by Fe-doping. It shows that Fe-doping is one of good choices to control electron density in InN.