Structure and optical properties of SiO2 films with ZnSe nanocrystals formed by ion implantation

Abstract

ZnSe nanocrystals have been formed in the silicon dioxide matrix by the sequential high-fluence implantation of Zn + and Se + ions at 500°C. After implantation a part of samples was annealed at 1000°C for 3 min using rapid thermal annealing. Structural and optical properties of ZnSe/SiO 2 nano-composite films were analyzed by means of Rutherford Backscattering Spectrometry, cross-sectional Transmission Electron Microscopy, Raman scattering and photoluminescence techniques. It was shown that a sequence of implantation affects structural and optical properties of synthesized ZnSe clusters. Based on the Raman scattering and photoluminescence data the samples for which Zn ions were implanted first exhibited a better ZnSe crystalline quality than those of reverse sequence of implantation, i.e. with Se ions implanted at the beginning. The bands of blue ZnSe band edge emission and green-red ZnSe deep defect level emission were revealed in the PL spectra of the as-implanted and annealed nano-composites. The PL spectral features observed in the blue region are due to the quantum-size effects in the ZnSe nanocrystals embedded into the silicon dioxide matrix. The PL intensity ratio of the deep defect band to the near edge emission is higher in the samples first implanted with Se ions, and Zn ions implanted next. The effect of rapid thermal annealing on structural and light-emitting properties was discussed.

Influence of the Order of Ion Implantation on Luminescent Spectrum of ZnSe Nanocrystals

“…The nanocrystals of ZnSe was formed by sequential implantation of Zn + and Se + ions with energies of 150 and 170 keV, respectively, in the silicon dioxide matrix [2]. The energies of ions were chosen for reasons of maximum overlap of the concentration profiles of the implanted atoms.…”

“…For example, recent study of silica glass luminescence during low energy H + , He + and O + irradiation performed at the 200 kV Ion Implanter was based on spectrum decomposition into four different emission bands by fitting Gaussian functions [13]. This paper presents the results of mathematical processing of photoluminescent spectra of ZnSe nanocrystals formed in an amorphous SiO 2 film by ion implantation [2].…”

“…Progress of science and technology requires the creation of new functional materials with special properties to solve various technical problems. In recent years, semiconductors and optical elements based on selenides have been widely studied and used [1][2][3]. Much attention is paid to the properties of nanosized crystals of zinc selenide (ZnSe) (see, for example, [1][2]4]).…”

“…In recent years, semiconductors and optical elements based on selenides have been widely studied and used [1][2][3]. Much attention is paid to the properties of nanosized crystals of zinc selenide (ZnSe) (see, for example, [1][2]4]).…”

“…They can be formed from zinc and selenium atoms, which are injected into the surface layer of the sample or epitaxial film by bombarding the surface with a beam of high energy ions of these elements. In [2,9], ZnSe nanocrystals were formed from implanted zinc and selenium atoms in the SiO2 layer, which was created by oxidation on the surface of a silicon substrate.…”