Fabrication And Photovoltaic Application Of Hierarchical Hetero-nanostructures

In this thesis, we surveyed the decisive factors for an excellent photoandoe ofsemiconductor sensitized solar cells （SSSCs）, and designed a structure of ZnO/CdShierarchical nanostructure. We developed a low-temperature process for facilesynthesis of ZnO/CdS hierarchical nanowires. Meanwhile, a green material, ZnFe₂O₄（ZFO）, was synthesized on carbon fibers. The main results are as follows:The ZnO nanowires were first prepared via a hydrothermal route and then thesecondary single-crystal CdS tips were grown on the ZnO nanowires byelectrochemical deposition, and the formation mechanism of CdS nanotips wasdiscussed in detail. The as-grown hierarchical ZnO/CdS nanowries are superior incharge separation as well as carrier transport, thus achieving higher open circuitvoltage, short circuit current and final conversion efficiency30%higher than thecommon coaxial nanocables with CdS nanocrystal shell on core ZnO nanowiresThe Fe₂O₃nanowires were synthetized on carbon fibers via a hydrothermal routefollowed by annealing treatment. Then Fe₂O₃nanowires were transferred into ZFOnanowires under high temperature, resulting in a ZFO/C hierarchical nanostructure.Though ZnO impurities were found existed in sample, we believe they can beeliminated by any chemical treatments. Such a structure is promising for theapplication in photovoltage area.