AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Thursday Sessions
       Session NS-ThM

Paper NS-ThM10
Indium Phosphide Nanocrystals formed by Sequential Ion Implantation into Fused Silica

Thursday, November 5, 1998, 11:20 am, Room 321/322/323

Session: Nanoscale Patterning and Modification
Presenter: D. Denmark, Fisk University
Authors: D.O. Henderson, Fisk University
R. Mu, Fisk University
A. Ueda, Fisk University
M.H. Wu, Fisk University
D. Denmark, Fisk University
C.W. White, Oak Ridge National Laboratory
A. Meldrum, Oak Ridge National Laboratory
R.A. Zuhr, Oak Ridge National Laboratory
Correspondent: Click to Email
Indium followed by phosphorous were implanted into optical grade fused silica at energies of 320 and 120 keV, respectively and at doses ranging from 1x10@super 16@ ions/cm@super 2@ to 1x10@super 17@ ions/cm@super 2@. The implanted substrates were annealed at 800°C for 1 h in a reducing atmosphere (5% H@sub 2@ +95% Ar). Vibrational and electronic spectra were recorded before and after annealing the samples. The vibrational spectra revealed a peak at 320 cm@super -1@ after annealing at 800°C. The intensity of this peak increased with ion dose and is assigned to the surface phonon of InP nanocrystals. XRD measurements confirmed the presence of crystalline InP and TEM showed particles with radii ranging from 4.6 to 11.6 nm. Electronic spectra of the annealed samples indicated that the energy of the band edge absorption is well below the bulk value of 969 nm. The band gap energies increased with decreasing ion dose and is attributed to quantum confinement of the exciton. The quantum confinement of the exciton is supported by the TEM measurements which demonstrated that the nanocrystals are nearly equal to or smaller than the InP exciton radius of 10.7 nm.