Controllable and Rapid Synthesis of Long ZnO Nanowire Arrays for Dye-Sensitized Solar Cells

Abstract

The hydrothermal method is widely used to synthesize ZnO nanowires for electrical and optical devices. However, the rapid synthesis of long vertically aligned ZnO nanowire arrays on a transparent conductive oxide substrate is still a challenge and also time-consuming. In this paper, we report a controllable and rapid growth of long ZnO nanowire arrays by a microwave heating method with fresh precursor solution continuously injected into the reactor. This method can avoid the growth stoppage and keep the concentration of the reactants in dynamic equilibrium during the whole reaction. It is found that the length of the nanowires increases linearly with growth time, and the growth rate is as high as 58−78 nm/min, producing ZnO nanowires with a length over 10 μm after growing for 2−3 h. When these nanowire arrays were used as the photoanodes of dyesensitized solar cells (DSSC), the power conversion efficiency of these ZnO nanowire-based DSSCs increases with the length of the nanowires, which is mainly attributed to the enlarged internal surface area and therefore dye-loading amount enhancement in the longer ZnO nanowires. This controllable and rapid method is useful for synthesizing ZnO or other ultralong 1D nanostructure for nanodevices.

Optimization of 3D ZnO brush-like nanorods for dye-sensitized solar cells

“…However, despite these improvements the maximum efficiency remains below 2%, where efficiencies of up to 10% are achievable using similar dye-electrolyte systems in combination with mesoporous TiO 2 photoanodes. 7 Considering that maximum efficiencies similar to the ones achieved in this work are reported in related literature on ZnO nanostructures in DSSCs, 3,[16][17][18][19][22][23][24][25] this supports the conclusion that there are fundamental limitations to the use of ZnO nanostructures in DSSCs. Despite this, the overall ndings reported hereinthat through careful control of processing conditions an optimum hierarchical nanostructure can be produced with a careful balance between optimised surface area and conductive pathwaysare highly relevant beyond this single application.…”

“…Therefore, to overcome this issue, ZnO has been proposed as an alternative material in DSSCs. 3,[16][17][18][19] Compared to TiO 2 , ZnO presents a similar band gap, improved electronic properties, such as higher electron mobility, as well as the ability to grow in both 1D and 2D morphologies through simple techniques 20 (e.g. hydrothermal growth).…”

A novel Bi 2 S 3 nanowire @ TiO 2 nanorod heterogeneous nanostructure for photoelectrochemical hydrogen generation

“…Recently, one-dimensional (1D) nanostructures such as nanotube, nanorod and nanowire have recently attracted considerable attention owing to their unique advantages [23,49]. Compared to the films comprised of nanoparticles, the films with highly ordered 1D nanostructure can provide direct electrical pathways that ensure the rapid collection of photogenerated electrons, leading to the reduced recombination of electron-hole pairs [50,51].…”

Recent Advances in 2D Inorganic Nanomaterials for SERS Sensing

“…ZnO is also of interest for the development of SERS substrates because it offers strong light confinement due to its high refractive index value which helps in enhancing the SERS signal, with nanostructured ZnO having been prepared with morphologies such as nanospheres, nanowires, nanorods, nanocones, nanoneedles, and nanobelts . Recently, the application of various ZnO‐based materials as SERS substrates has been reviewed and two methods emphasized for improving the enhancement obtained: 1) heavy element doping and 2) preparing composites of nano‐ZnO with noble metals .…”