The Research On Preparation And Optoelectronic Performance Of Silver Nanowires Silica Antireflection Composite Transparent Conductive Films

Silver nanowires（AgNWs）can achieve high transmittance at very low sheet resistance and have always been the hot research material which is expected to replace indium tin oxide（ITO）and fluorine doped tin oxide（FTO）in optoelectronic devices.To further optimize the optoelectronic performane of AgNWs,the following methods have been adopted in recent years:（i）building composite structures;（ii）post treatment of AgNWs;（iii）controlling the nanowires structure via modifying their aspect ratios for scattering less light.Such work on AgNWs film mainly focuses on the improvement to conductivity,however there is no obvious increase to the optical transparency,in which it even appears a little drop.Herein,we introduced nano-antireflection arrayed structure to improve the optoelectronic performance and moderate the interface property of the film.Eventually we obtain the controllable new transparent conductive films with excellent optical performance.Then,combined with graphene oxide（GO）,the nanowire junctions are effectively wrapped to improve electrical property.And combined with titanium dioxide（TiO₂）as the protective layer to optimize optoelectronic performance and improve the thermal stability of the film.The AgNWs composite transparent conductive films with superior optoelectric performance and good stability are obtained through all solution-processed method with low cost and facile operational techniques,demonstrating their potential for large-scale application prospects and good development in the photoelectric fields.The specific research content is as follows:（1）The research on preparation and properties of AgNWs composite silica antireflection structure transparent conductive films.The solid silica nanospheres（SSNSs）array was assembled onto the substrate to elevate the transmittance of the substrate from 92.25%to 99.11%.Then the prepared AgNWs ink of different densities was spin coated onto the antireflection layer.The fabricated AgNWs/SSNSs composite transparent conductive films can achieve utra-low sheet resistance of 49.43Ω·sq^-1 with excellent optical transmittance of 99.84%,which have exceeded ITO.Moreover,the SSNSs antireflection structure is favorable to moderate the interface property of the film,regulating the water contact angle from 81.51° to30.79°.The AgNWs/SSNSs composite transparent conductive films with excellent performance have been fabricated via facile all-solution processed method,free from considerable intrinsic post treating process.It shows the advantages of low fabrication cost and simple operation process.（2）GO was introduced to wrap around the AgNWs and the GO/AgNWs-SiO₂antireflection structure composite films were constructed to further optimize the electrical property.GO functions to solder the AgNWs junctions and dramatically reduces the inter-nanowire contact resistance.Firstly,based on hollow and solid composite SiO₂ nanospheres,the‘moth-eye’like nano-antireflection structure was constructed,which further increased the optical transmittance free from complex etching process.The transmittance of the substrate enhanced from 92.25%to 99.46%.The controllable GO/AgNWs-SiO₂ antireflection structure composite transparent conductive films can be obtained with optical transmittance reaching 98.67%at 550 nm under 26.26Ω·sq^-1 of sheet resistance.The composite structure creatively combines GO with the‘moth-eye’like nano-antireflection structure to achieve the synergetic improvement of optoelectronic performance of the AgNWs network structure,which embodies dual advantages of both structure and performance.（3）Titanium dioxide（TiO₂）was introduced as the protective layer,and the TiO₂/AgNWs-SiO₂ antireflection structure composite films were constructed to further optimize the optoelectronic performance of the AgNWs network structure and improve its thermal stability.The composite transparent conductive films can reach 99.93%of the optical transmittance at 550 nm under 21.10Ω·sq^-1 of sheet resistance.AgNWs are easily melted into chains of nanospheres at the temperature above 200℃ due to Rayleigh instability.The composite transparent conductive films can remain their conductive network structure characteristics even annealed under 400℃ high temperature environment.At this time,the sheet resistance declined to 210.9Ω·sq^-1with 99.27%of high optical transmittance,which was significantly improved compared with the unprotected AgNWs.The composite thin film structure has the advantages of facile fabrication process with low cost,superior optoelectronic performance and good thermal stability.