Analysis of optical spectra and SH parameters of V3+ centers in ZnO crystals

Wei, Qun; Guo, Lixin; Wei, Bing; Yang, Ziyuan

doi:10.1016/j.optmat.2012.01.011

Cited by 3 publications

(1 citation statement)

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“…It is expected that substitution of Zn 2+ (0.60 Å) with smaller V 5+ ions (0.36 Å) induces the shift of the diffraction peak toward higher 2θ angles, while bigger V 3+ ions (0.64 Å) should result into the shift toward lower 2θ values. Despite being six-fold coordinated, theoretical studies showed that V 3+ may replace Zn 2+ ions in wurtzite structures as well, although not occupying the same site 52 53 . Additionally, V 3+ may also enter into the interstitial position of the ZnO lattice due to the similarity between ionic radii of V 3+ (0.…”

Section: Resultsmentioning

confidence: 99%

Lead-free piezoelectrics: V3+ to V5+ ion conversion promoting the performances of V-doped Zinc Oxide

Laurenti

Castellino

Perrone

et al. 2017

Sci Rep

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Vanadium doped ZnO (VZO) thin films were grown by RF magnetron sputtering, starting from a ZnO:V ceramic target. The crystal structure, chemical composition, electric and piezoelectric properties of the films were investigated either on the as-grown thin films or after a post-deposition rapid thermal annealing (RTA) treatment performed at 600 °C for different lengths of time (1 and 5 min) in an oxygen atmosphere. Substitutional doping of Zn2+ with V3+ and V5+ ions strongly deteriorated the hexagonal wurtzite ZnO structure of the as-grown thin films due to lattice distortion. The resulting slight amorphization led to a poor piezoelectric response and higher resistivity. After the RTA treatment, strong c-axis oriented VZO thin films were obtained, together with a partial conversion of the starting V3+ ions into V5+. The improvement of the crystal structure and the stronger polarity of both V3+ – O and V5+ – O chemical bonds, together with the corresponding easier rotation under the application of an external electric field, positively affected the piezoelectric response and increased conductivity. This was confirmed by closed-loop butterfly piezoelectric curves, by a maximum d33 piezoelectric coefficient of 85 pm·V−1, and also by ferroelectric switching domains with a well-defined polarization hysteresis curve, featuring a residual polarization of 12.5 μC∙cm−2.

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Section: Resultsmentioning

confidence: 99%