Origin of room temperature broadband light emission and carrier dynamics in Ag ion-implanted Silicon nanocrystals

Abstract

We studied the origin of broad band light emission in the Ultraviolet (UV) to the red from silicon nanoparticles fabricated using a single low energy (32 keV) silver ion implantation with a fluence of 5*10 15 ions/cm 2 in crystalline Si. It is found from a systematic study of the annealing carried out at certain temperatures that the spectral characteristics in the UV and blue region remains unchanged except for the enhancement of light emission intensity due to annealing. The annealing results in nucleation of Ag nanoclusters in the vicinity of Si nanoparticles which enhances the emission intensity. Time-resolved photoluminescence (TRPL) measurement demonstrates that the emission originates from both highly localized defect bound excitons at the nanoscale Si interface, as well as surface and interface traps associated with the increased surface area of the Si nanocrystals. The emission in the UV is due to interband transitions from localized excitonic states at the interface of Si/SiO 2 or from the surface of Si nanocrystals. The radiative efficiency of the UV and the green emission from the Si nanoparticles can be modified by the localized plasmons interaction induced by the nucleation of Silver nanoparticles on controlled annealing of the samples. Broadband emission ranging from the UV to the red wavelength range can be obtained on Ag implanted onto a single silicon substrate.

Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

“…Similar interference effects might have occurred for the light emitted from the C nanoclusters in the annealed sample in the present study. Broad-band emission was also observed by Singh et al in 45-keV silver-implanted Si samples excited by a 325 nm HeCd laser [32]. The authors suggested defects as the origin of such broad-band emission.…”

Improving Passivation Process of Si Nanocrystals Embedded in SiO2Using Metal Ion Implantation

“…It has been observed that ion metal implantation could quench the PL from Si-NCs [12,13]. On the other hand, the PL signal from Si-NCs can be enhanced by the localized plasmon interaction induced by the nucleation of metal nanoparticles under controlled annealing [14,15]. en, the enhancement of the PL emission from the integrated system studied in this work could have two contributions.…”

Plasmonic Nanoparticles in Dielectrics Synthesized by Ion Beams: Optical Properties and Photonic Applications

“…[ 52,53 ] Obviously, the mentioned NP appearance process above is closely related to the implantation parameters (e.g., fluence, energy, and ion species), the annealing parameters (e.g., temperature, time, and atmosphere), and the matrix materials. [ 54–59 ] In general, the average size of NPs depends on the implanted fluence (normally larger than 10 16 ions cm −2 ), and the NP distribution lies on the implanted energy (range from tens of keV to several MeV). [ 60 ] The optimal annealing temperature (vary from 100 to 1000 °C) and time (tens of minutes to several hours) are strongly associated with the component of NPs and matrixes, in the meanwhile, different atmosphere shows disparate impact on the NP formation as well.…”