The electronic properties and nitrogen bonding configurations are investigated in dilute InNxSb1-x alloys grown by molecular beam epitaxy using a mixed nitrogen and hydrogen plasma. High-resolution electron-energy-loss spectroscopy is used to observe annealing-induced changes in the conduction band electron plasma frequency and plasmon lifetime. X-ray photoelectron spectroscopy of the N 1s core level indicates that a large proportion of the nitrogen in the InNxSb1-x alloy is contained within neutral N–H complexes. Annealing at 300 °C removes hydrogen from these complexes, increasing the concentration of isoelectronic nitrogen acceptors. This increases the ionized impurity scattering and reduces the background conduction electron density. © 2003 American Institute of Physics.