Resonant localized donor state above the conduction band minimum in InN

We have studied the pressure dependence of Hall electron concentration and mobility in degenerated, not intentionally doped InN samples. The results obtained for a whole set of samples with electron concentrations from 5.4 × 10 17 cm − 3 to 3.3 × 10 18 cm − 3 consistently reveal the existence of a localized donor type state, resonant with the conduction band. Its energy position is estimated to be about 80-90 meV above the bottom of the conduction band. This donor state is not the only source of electrons in these not intentionally doped samples and can be entirely populated and hidden in samples with very high electron concentrations.