Preparation Of Metal Nanomaterials And Their Applications In Solar Cells And Transparent Conductors

Metallic nanomaterials with special optical properties and excellent electrical conductivityhave attracted a lot of attention and been applied dye-sensitized solar cells?DSSCs?,flexible transparent conductive electrodes?FTCEs?,drug release,biocatalysis,low energy emission window and other optical materials.With the continuous maturation of the preparation technology and deepening of performance research of metal nanomaterials,more and more nanostructures have been fabricated,which can greatly enrich the application of metal nanomaterials in more fields.The metallic nanomaterials have unique localized surface plasmon resonance property?LSPR?,which can absorb most of the energy of incident sunlight,reduce the energy of reflected light and finally increase the capture of the sunlight.Therefore,combining metallic nanomaterials with the photoanode of dye-sensitized solar cell to prepare a cell with a surface plasmon effect can effectively improve the power conversion efficiency of DSSCs.The continuous maturation of preparation technology makes the metal nanowire gradually become the main material for preparing flexible transparent electrodes.Compared with traditional indium tin oxide?ITO?,metal nanowires are not only easy to prepare,but also rich in content and with good electrical conductivity and flexibility.Therefor,the metal nanowires are more suitable for the preparation of flexible devices.Different structural metal nanomaterials are designed and synthesized,which were futher used to prepare dye-sensitized solar cells with specular power conversion efficiency and flexible transparent conductors with high performance.The main contents and conclusions of the work are as follows:?1?Dye-sensitized solar cells with surface plasmon effect was prepared by mixing gold nanospheres and nanorods?AuNSs,AuNRs?.The mixed gold nanomaterials?AuNCs@SiO₂?with silica?SiO₂?shell were prepared by the hydrolysis of tetraethoxysilane.AuNCs@SiO₂ were mixed into TiO₂ photoanode with certain proportion to prepare DSSCs with surface-plasmon effect.The research results showed that the power conversion efficiency of DSSCs can be effectively improved by properly doping Au NCs@SiO₂,?2?Prepareation of CuNWs@TiO₂ and its application in dye-sensitized solar cell.Copper nanowires?CuNWs?were prepared by the solution method.Tetrabutyl titanate was further hydrolyzed to prepare titania?TiO₂?wrapped CuNWs to obtain core-shell structure?CuNWs@Ti O₂?.The effects of different proportions of core-shell nanostructures CuNWs@TiO₂ on the performance of DSSCs were investigated.The results indicated that the shell-core nanostructures of CuNWs@TiO₂ can effectively improve the power conversion efficiency of DSSCs.?3?Synthesis of ultra-long silver nanowires and their applications in flexible transparent conductive electrode?FTCE?materials.Ultra-long silver nanowires?AgNWs?were prepared by reducing silver nitrate?AgNO₃?using high molecular weight polyvinylpyrrolidone?PVP?as the capping agent in ethylene glycol?EG?solution.The products were purified using a filter cloth to obtain AgNWs with uniform length exceeding 250?m.The morphology and structure of the nanowires were characterized.Afterwards,the silver nanowires were evenly coated on a polyethylene terephthalate?PET?substrate to prepare FTCEs by means of spin coating.The results showed that ultra-long AgNWs can be used to produce FTCEs with excellent properties.?4?Preparation of FTCEs based on ultra-long copper nanowires?CuNWs?.Ultra-long CuNWs were prepared in water/polyol system.By researching the experimental process and setting different experimental parameters,the factors affecting the morphology and dispersibility of ultra-long CuNWs were systematically studied.Polydimethylsiloxane?PDMS?-based FTCEs were prepared using a combination of vacuum filtration,hydrogen reduction and spin coating method.Studies showed that the FTCEs based on ultra-long CuNWs have excellent performance and can be used to prepare a flexible wearable device to detect the movement of a finger joint.?5?Synthesis of ultra-thin semi-circular copper nanowires?SCuNWs?and their application in flexible transparent conductive electrodes.The SCuNWs were synthesized in ethanol solution.Various factors which can affect the morphology of nanowires were systematically studied.The prepared SCuNWs were coated on polyethylene terephthalate or polydimethylsiloxane substrates to fabricate FTCES.The results showed that:the FTCEs manufactured with SCuNWs exhibit high mechanical stability during stretching and bending process,which indicated that SCuNWs may have a great prospect in the field of flexible optical devices.