Manganese-doped silicon nanocrystals (Si NCs) in which Mn was in its most likely substitutional or interstitial location were investigated. Large differences in magnetic moment were found between Si NCs doped with substitutional Mn and those doped with interstitial Mn. For all the doped Si NCs, quantum confinement affected the electronic states of majority spin more significantly than those of minority spin. As the NC size changed from 1.2 to 1.5 nm, the spin flipping of electronic transition across the NC optical gap occurred for Si NCs doped with substitutional Mn. This led to significant changes in the optical absorption of Si NCs. It was likely that such spin-flipping also happens for larger (>1.7 nm) Si NCs doped with interstitial Mn.

Silicon Nanocrystals Doped with Substitutional or Interstitial Manganese. X.Chen, X.Pi, D.Yang: Applied Physics Letters, 2011, 99[19], 193108