Electron spin resonance measurements of N-rich hydrogenated amorphous material, where x was greater than 1.3, were performed as a function of the temperature and microwave power. This revealed a second paramagnetic center, in addition to the well-known 3-fold-coordinated Si dangling bond (K center). This second center was a neutral 2-fold coordinated N atom that was bonded to two Si atoms (N20 center). It was suggested that the predominant defects in amorphous hydrogenated SiN1.6 were compensated K3+ and N2- electron and hole traps, respectively.

D.Q.Chen, J.M.Viner, P.C.Taylor: Solid State Communications, 1996, 98[8], 745-50