Synthesis of different ZnO nanostructures by modified PVD process and potential use for dye-sensitized solar cells

Abstract

a b s t r a c t Different ZnO nanostructures were synthesized by physical vapor deposition on glass-ITO substrates. Nanowires and nanosheets were obtained by a single step process using gold nanoparticles and gold thin films as catalyst. 3D nanoarchitectures were obtained by a two-step modified process; the morphology of these structures depends on the catalyst used for the second deposition: gold nanoparticles or zinc acetate seeds. All the nanostructures were characterized by SEM and TEM analyses, which showed the different morphology under same conditions of temperature, pressure, oxide precursor and deposition time. Dye-sensitized solar cells based on these ZnO structures were successfully assembled, using N179 as sensitizer with efficiencies between 0.1% and 0.5%. In spite of the low efficiency of the cells, a novel double PVD process is presented and its integration capability into solar cell devices has been proven.

Ultraviolet Sensors Based on Two-Dimensional Zinc Oxide Structures

“…A metal-organic chemical vapour (MOCVD) process was also used to prepare 2D ZnO nanowalls on GaN/Al 2 O 3 substrates [47]. Physical vapour deposition (PVD) was used to synthesise ZnO nanosheets for dye solar cell applications [48] High-pressure pulsed laser deposition (PLD) method was also used for growing 2D ZnO nanowalls. In addition, it was found that the lattice parameter of the substrate used for the growth of 2D ZnO plays a crucial rule in the growing process.…”

“…It was found that controlling the experiment parameters results in significant changes in the morphology of the prepared 2D ZnO. Parameters such as substrate lattice mismatch between the substrate and the film will result in the modification of the ZnO structure [48]. The morphology of ZnO structures can be modified by adding salts, such as KCl and CH 3 COONH, to the electrolyte in the electrodeposit method [41].…”

ZnO Quasi-1D Nanostructures: Synthesis, Modeling, and Properties for Applications in Conductometric Chemical Sensors

“…Physical vapor deposition (PVD) is a technique for the preparation of metal oxide nanostructures that has been optimized during recent years [29][30][31]. In this case, The ZnO nanowires can grow according to two different mechanisms: vapor-liquid-solid or vapor-solid, depending on both the source material and destination growth sites [30,31].…”

“…In this case, The ZnO nanowires can grow according to two different mechanisms: vapor-liquid-solid or vapor-solid, depending on both the source material and destination growth sites [30,31]. The PVD system consists of a tubular furnace with regulable temperature which is connected to a rotary vacuum pump in order to control the pressure inside the furnace.…”

“…The morphology modifications of the fabricated nanostructures are carried out by changing the condensation temperature, the pressure inside the tubular furnace, the carrier gas flow and composition, the deposition time, and the catalyst on the target substrates. The PVD system can also be used for direct thermal oxidation of the metallic zinc to prepare ZnO nanostructures [30,31]. The thermal growth consists of two steps: metallic layer deposition and thermal oxidation.…”