Electroluminescence of monodispersed silicon nanocrystallites synthesized by pulsed laser ablation in inert background gas

Abstract We have characterized dc-excited light-emitting properties of monodispersed silicon (Si) nanocrystallites (nc-Si) synthesized by pulsed laser ablation in inert background gas. In a case where the monodispersed nc-Si were passivated by an indium oxide (In 2 O 3 ) layer without breaking the vacuum, the electroluminescence (EL) spectrum had a narrow bandwidth of 0.15 eV peaked at slightly higher energy region (1.17 eV) than the bulk Si energy gap (1.11 eV), at room temperature. On the other hand, broad visible EL (peak: 1.7 eV, bandwidth: 0.46 eV) appeared when the monodispersed nc-Si were exposed to air before In 2 O 3 passivation. These light-emitting mechanisms are discussed in relation to quantum confinement effects and oxide-related emission centers.