A study of the photoluminescence characteristics of InxGa1-xN alloys in which the Fermi level is controlled by energetic particle irradiation is reported. In In-rich InxGa1-xN the photoluminescence intensity initially increases with irradiation dose before falling rapidly at high doses. This unusual trend is attributed to the high location of the average energy of the dangling-bond-type native defects (the Fermi level stabilization energy). Our calculations of the photoluminescence intensity based on the effect of the electron concentration and the minority carrier lifetime show good agreement with the experimental data. Finally the blueshift of the photoluminescence signal with increasing electron concentration is explained by the breakdown of momentum conservation due to the irradiation damage.