ZnO@TiO2 Core/Shell Nanowire Arrays with Different Thickness of TiO2 Shell for Dye-Sensitized Solar Cells

Abstract

The ZnO@TiO2 core/shell nanowire arrays with different thicknesses of the TiO2 shell were synthesized, through depositing TiO2 on the ZnO nanowire arrays using the pulsed laser deposition process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that these core/shell nanowires were homogeneously coated with TiO2 nanoparticles with high crystallinity, appearing to be a rather rough surface compared to pure ZnO nanowires. The efficiency of ZnO@TiO2 core/shell structure-based dye-sensitized solar cells (DSSCs) was improved compared with pure ZnO nanowires. This is mainly attributed to the enlarged internal surface area of the core/shell structures, which increases dye adsorption on the anode to improve the light harvest. In addition, the energy barrier which formed at the interface between ZnO and TiO2 promoted the charge separation and suppressed the carrier recombination. Furthermore, the efficiency of DSSCs was further improved by increasing the thickness of the TiO2 shell. This work shows an efficient method to achieve high power conversion efficiency in core/shell nanowire-based DSSCs.

Towards Integration of Two-Dimensional Hexagonal Boron Nitride (2D h-BN) in Energy Conversion and Storage Devices

“…However, by increasing the surface area of TiO 2, the number of surface states increases, leading to higher rates of recombination [175]. Moreover, the heat treatment of TiO 2 at temperatures around 450 • C to form the anatase phase which is favorable for DSSC, leads to the formation of oxygen vacancies [176]. Consequently, there will be more surface deficiencies deteriorating the cell's performance.…”

Application of ultrathin TiO2 layers in solar energy conversion devices

“…For example, Liu et al used PLD to deposit thin TiO 2 shells on ZnO nanowire arrays for DSSC. 51 Wang et al also deposited 11 nm thick anatase TiO 2 shells on ZnO nanorods by radio frequency magnetron sputtering. 52…”

“…Furthermore, other PVD techniques are also applicable to prepare TiO 2 thin films in solar energy conversion devices. For example, Liu et al used PLD to deposit thin TiO 2 shells on ZnO nanowire arrays for DSSC 51 . Wang et al also deposited 11 nm thick anatase TiO 2 shells on ZnO nanorods by radio frequency magnetron sputtering 52 …”

Effect of Nano-TiO2 Composite on the Fertilization and Fruit-Setting of Litchi

“…nTiO 2 can act as a protective layer by forming a consistent film that can absorb oxygen with a specified sensitivity [ 19 ]. TiO 2 films are also widely used as photoelectrodes to prepare dye-sensitized solar cell devices [ 20 ]. nTiO 2 is readily absorbed and collected by crops due to its small particle size and large specific surface area and impacts agricultural productivity and quality [ 21 , 22 ].…”