Influences of Ga Doping on Crystal Structure and Polarimetric Pattern of SHG in ZnO Nanofilms

Abstract

The second-harmonic generation (SHG) in gallium doped ZnO (GZO) nanofilms was studied. The Ga doping in GZO nanofilms influenced the crystal structure of the films, which affected SHG characteristics of the nanofilms. In our experiments, a strong SHG response was obtained in GZO nanofilms, which was excited by 790 nm femtosecond laser. It was observed that the Ga doping concentrations affected, not only the intensity, but also the polarimetric pattern of SHG in GZO nanofilms. For 5.0% doped GZO films, the SHG intensity increased about 70%. The intensity ratio of SHG between the incident light polarization angle of 90° and 0°changed with the Ga doping concentrations. It showed the most significant increase for 7.3% doped GZO films, with an increased ratio of c/a crystal constants. This result was attributed to the differences of the ratios of d33/d31 (the second-order nonlinear susceptibility components) induced by the crystal distortion. The results are helpful to investigate nanofilms doping levels and crystal distortion by SHG microscopy, which is a non-destructive and sensitive method.

Gallium-Doped Zinc Oxide Nanostructures for Tunable Transparent Thermoelectric Films

“…This is probably because the Ga doping level is approaching to the saturation point in the ZnO thin film. The similar observation has been reported . Note also that no characteristic diffraction peaks of the Ga 2 O 3 crystal structure were observed [such as the (111) peak at 35.2°].…”

“…The similar observation has been reported. 38 Note also that no characteristic diffraction peaks of the Ga 2 O 3 crystal structure were observed [such as the (111) peak at 35.2°]. The d-spacing of the (002) lattice planes is determined using Bragg's law 2d sin θ = nλ, where d is the inter planar spacing, θ is the scattering angle, n is a positive integer, and λ is the angle of the incident wave (λ = 0.15,406 nm for Xray).…”

Symmetry breaking in 2D materials for optimizing second-harmonic generation

“…Another effective way to breaking centrosymmetry is by doping magnetic or rare earth ions and applying the electric field [74][75][76][77]. Zhang et al [78] showed that the impurity atom breaks the inversion symmetry of bilayer graphene, leading to the nonzero value of χ (2) .…”

Enhancement of the linear, nonlinear and optical limiting properties of epoxy resin decorated by zinc oxide nanoparticles

“…Among various known materials, zinc oxide (ZnO) has a large exciton binding energy of 60 meV along with a direct wide band gap of 3.37 eV in ambient condition which qualifies its applications in many areas related to energy storage super capacitors [25], UV and gas sensors [26][27][28][29][30], optoelectronic devices [31,32], antireflection coatings [33], biosensors and photocatalyst [34,35] etc. Diversity of researches have been directed to study the ZnO nanoparticles in different shapes and goals such as photo luminescent ZnO nanoparticles for biological applications [36], ZnO nanoparticles modified carbon paste electrode for cyclic voltammetric study for drug analysis [37], for using in co-precipitation method in determining synthesis and characterization of Fe doped ZnO nanoparticles [38], influence of Ga doping on crystal structure and polarimetric pattern of SHG in ZnO nano films [39], in imaging of ZnO nanoparticles penetration in human skin in vitro and in vivo [40] to name a few. Several investigations were conducted to study the optical properties of ZnO based nanostructures such as ZnO-SiO 2 nanocomposites [41], zinc oxide doped aluminium films [42], ZnO nanoparticles [43], Mn-doped ZnO thin films [44], ZnO/polyvinyl alcohol (PVA) nanocomposite films [45], ZnO-Ag nanocomposites [46,47], ZnO/polymethyl methacrylate nanocomposite films [48], ZnO nanorods [49][50][51][52], Au/ZnO nanoparticale arrays [53], nanocomposite foils [54] and ZnO/polystyrene nanocomposite films [55].…”