Ion-implantation induced nano distortion layer and its influence on nonlinear optical properties of ZnO single crystals

Abstract

Second harmonic generation (SHG) and X-ray diffraction rocking curves of high-quality ZnO single crystals implanted by different ions (He, Cu, and Zn) were investigated. Interestingly, it was found that both He- and Zn-implanted samples show a convinced increment in SHG efficiency while the Cu-implanted one does not. X-ray diffraction rocking curves of the samples show satellite structures, and the simulations firmly reveal the formation of quasi-interfaces inside He- and Zn-implanted crystals. These quasi-interfaces lead to SHG improvement in the two samples. Polarization dependence of SHG of the samples on the excitation light also evidences this conclusion.

Who make transparent ZnO colorful? – Ion implantation and thermal annealing effects

“…The Cu ions of energy 100 keV were implanted with a fluence of 10 14 cm À2 at the substrate temperature of 300 C. The Cu depth profile peaked at 40.0 nm (as calculated by TRIM program and confirmed by secondary-ion mass spectroscopy). The Zn ions of energy 500 keV were implanted with a fluence of 10 14 cm À2 at the substrate temperature of 300 C. The Zn implantation would result in implantation depth profile with peak at 210.0 nm [28]. Variable-temperature PL measurements were carried out on the samples that were mounted on the cold finger of a Janis closed cycle cryostat providing a varying temperature range of 3.5e300 K. The excitation source was a Kimmon He-Cd 325 nm continuous wave laser with maximum output power of 40.0 mW.…”

Fabrication of ZnO Nanostructures

“…Zn-polar ZnO showed higher d eff values as compared to O-polar ZnO. Additionally was found that implantation of H and Zn into ZnO single crystals results in a convinced increment of SHG, while Cu implantation does not [191].…”

Nature of red luminescence band in research-grade ZnO single crystals: A “self-activated” configurational transition

“…13 From the XRD rocking curves (not shown here), we can see that the ion implantation causes several satellite structures located on both sides of the main diffraction peak, indicating the formation of defects and lattice distortion within several hundreds of nanometers. 13 By adopting the kinematic model developed from the dynamical X-ray diffraction theory for uniform single crystal to fit the experimental XRD rocking curves, we can get the information of strain depth distribution along the implantation direction. In the as-Zn-implanted ZnO sample, the compressive and tensile strains are found to be simultaneously present.…”

“…Under these conditions, implanted Zn ions in ZnO have a concentration depth profile peaking at a depth of 210.0 nm from the implanted surface. 13 In the subsequent PL measurements, the samples were mounted on the cold finger of a Janis closed cycle cryostat providing a varying temperature range of 3. Hamamatsu R928 photomultiplier.…”

“…Moreover, the compressive strain distribution appears in the region near the implantation surface and then the tensile strain distribution successively appears. 13 This means that vacancy-type defects are produced in the shallower regions while the interstitial defects are introduced in the deeper regions from the surface. It is known that the local strain in the ion-implanted region is usually induced by incorporation of implanted ions into host crystal.…”