Short lifetime photoluminescence of amorphous-SiN x films

We observed photoluminescence (PL) of amorphous-SiNx films which showed a short radiative lifetime of about 1 ns. The spectrum form is Gaussian centered at around 2.2 eV. The samples were prepared by low-pressure chemical vapor deposition with SiH2Cl2 and NH3 gases. We propose an electron-phonon coupling model for the PL, assuming that the coupling phonon is Si–H or N–H vibrational mode and the bond length changes over 0.1 Å at an excited state due to the strong interaction.