Synthesis of ZnO tetrapods for flexible and transparent UV sensors

Abstract

ZnO tetrapods (ZnO-Ts) were synthesized in a vertical flow reactor by gas phase oxidation of Zn vapor in an air atmosphere. The morphology of the product was varied from nearly spherical nanoparticles to ZnO-Ts, together with the partial pressure of Zn and reaction temperature. MgO introduced during synthesis, increased the band gap, the optical transparency in the visible range, and also changed the ZnO-T structure. Fabricated flexible transparent UV sensors showed a 45-fold current increase under UV irradiation with an intensity of 30 μW cm(-2) at a wavelength of 365 nm and response time of 0.9 s.

A Novel Method for Continuous Synthesis of ZnO Tetrapods

“…It has gained significant attention because of unique optical, piezoelectric and magnetic properties, as well as capability of band gap tuning 1 . Non-catalytically grown ZnO nanostructures can be observed in various morphologies such as nanowires 2 , nanobelts 3 , and tetrapods 4,5 . The latter has promising applications in solar cells 6 , lasers 7 , field emitters 8 , UV and gas sensors 1,9 .…”

“…ZnO-Ts can be produced in the lab scale by a hydrothermal process 9 , from the mixture of ZnO and C 12 , in a chemical vapor transport and deposition system 13 . Moreover, ZnO-Ts can be synthesized from Zn powder 14 and collected from reactor walls 15,16 or filtered at the outlet of the reactor 4,17 . Direct synthesis of ZnO-Ts from the metal vapor has obvious advantages of low temperature process and high yield.…”

High performance UV sensor based on individual ZnO nanowire and photoelectric properties of individual ZnO nanowire surface in different atmospheres

“…It is well known that the recovery speed of photoresponse is governed by adsorption and desorption of oxygen molecules on the surface [12,19,20,21]. Because of the high surface-to-volume ratio, the surface states can significantly affect the photogenerated carriers and, in turn, the transport and photoconductivity of the ZnO nanowire.…”

ZnO Nanowires for Dye Sensitized Solar Cells

“…Applying the mentioned methods, ZnO NWs could be synthesized in complex forms (Figure 4) such as nanoforest [47], tetrapods [49,50], hierarchical nanowires [48], coral-shaped nanostructures [51], nanocactus [24], flower-like [52] and many others [53][54][55] by simply controlling the crystal grow direction.…”