The results of studies of the photoexcitation spectra of epitaxial InN layers formed by molecular-beam epitaxy with the plasma activation of nitrogen are reported. The concentration of free charge carriers in the layers is 10-10 cm. The photoconductivity, photoluminescence, and absorption spectra exhibit a shift of the long-wavelength threshold of interband transitions in accordance with the Burstein-Moss effect for n-InN with different concentrations of equilibrium electrons. In the samples, absolute negative photoconductivity with a nanosecond relaxation time is observed. The results of photoelectric, absorption, and luminescence spectroscopy experiments are correlated with the technological parameters and electron microscopy data. [ABSTRACT FROM AUTHOR]