Fabrication of ZnO nanoparticles in SiO2 by ion implantation combined with thermal oxidation

Abstract

Zinc-oxide (ZnO) nanoparticles (NPs) are fabricated in silica glasses (SiO2) by implantation of Zn+ ions of 60 keV up to 1.0×1017ions∕cm2 and following thermal oxidation. After the oxidation at 700 °C for 1 h, the absorption in the visible region due to Zn metallic NPs disappears and a new absorption edge due to ZnO appears at ∼3.25eV. Cross-sectional transmission electron microscopy confirms the formation of ZnO NPs of 5–10 nm in diameter within the near-surface region of ∼80nm thick and larger ZnO NPs on the surface. Under He–Cd laser excitation at λ=325nm, an exciton luminescence peak centered at 375 nm with FWHM of 113 meV was observed at room temperature.

Zn nanoparticles irradiated with swift heavy ions at low fluences: Optically-detected shape elongation induced by nonoverlapping ion tracks

“…Detailed fabrication conditions and fundamental properties of the NPs are described in our previous papers. [26][27][28][29][30][31] The silica samples containing Zn NPs were irradiated with 200 MeV Xe 14+ ions at room temperature (RT) using the tandem accelerator at the Japan Atomic Energy Agency, Tokai Research and Development Center (JAEA-Tokai). The electronic and nuclear energy losses, and the projected range of 200 MeV Xe ion in SiO 2 , were estimated from SRIM2008 code 32 and are summarized in Table I.…”

Room-temperature single-photon emission from zinc oxide nanoparticle defects and their in vitro photostable intrinsic fluorescence

“…In this paper, we present single-photon emission from defects in ZnO NPs formed by Zn ion implantation followed by thermal oxidation [42,43,50]. We observe red defect emissions under 532 nm excitation at room temperature, where the defects exhibit blinking characteristics with occasional photostability.…”

“…ZnO NPs were created by 64 Zn ion implantation at 60 keV with a fluence of 1.0 × 10 17 ions/cm 2 followed by the thermal oxidation of silica glass [42,43]. At an oxidation temperature of 600°C, most of the Zn ions are converted into the Zn metal and remain in this phase.…”

“…At an oxidation temperature of 600°C, most of the Zn ions are converted into the Zn metal and remain in this phase. At temperatures between 700°C and 800°C, the Zn metal begins to convert to ZnO and smaller NPs appear within the substrate with larger NPs aggregating on the surface [42,43].…”

“…Single-photon emission was overlooked for decades because material scientists generally perform ensemble (i.e. bulk) measurements [42,43], which end up sampling multiple optical defects. A thorough knowledge of the growth conditions and introduced defects coupled with high-resolution fluorescence microscopy, alongside density functional theory calculations, can yield the correct chemical origin of the defects.…”