| Transparent conductive oxide?TCO?has become an important basic material in microelectronics and optoelectronics industry because of its optical transmittance and electrical conductivity,and is widely applied to optoelectronics devices such as solar cells,light-emitting diodes,liquid crystal displays,thin film transistors and touch screens.Among various TCO materials,fluorine doped tin oxide?FTO?film has attracted much attention due to its advantages of good thermal and chemical stability,mechanical durability,easy etching,non-toxic and harmless,and low price,etc.,and has become one of the main substitutes for tin-doped indium oxide?ITO?.However,the photoelectric property of the original FTO film is unable to meet the increasing market demand.In order to improve the photoelectric property of FTO,this paper proposes to conduct laser etching on the commercially available FTO film,then deposit Ag layer on the surface of the laser-etched film and annealed it in the furnace,and finally deposit AZO layer on the surface of the film prepared by the above steps and treat it with laser annealing.The effects of this process on the surface morphology,crystal structure and photoelectric properties of FTO films were studied,and some significant results were obtained.1.Grid pattern was etched on the surface of FTO film by 532 nm nanosecond pulse laser.Influences of laser with different defocusing amounts,laser fluences and scanning speeds on the surface morphology and photoelectric properties was studied.The mechanism of laser etching FTO film is discussed.Results showed that when the amount of defocusing amount was 0,the laser fluence was 0.4 J/cm2 and scanning speed was 10 mm/s,grooves forming on the FTO film had the best quality and its roughness is slightly larger than the original FTO film.Moreover,the existence of grooves barely affected the photoelectric property of the film.Average transmittance of the film was 77.63%,the sheet resistance was 10.27?/sq and the figure of merit was 0.774×10-2?-1.Laid the foundation for the subsequent preparation of Ag embedded FTO-based transparent conductive film2.Ag layer with a certain thickness was deposited on the surface of laser-etched FTO film by magnetron sputtering,and then annealed in the medium temperature tube furnace.Effects of Ag layer thickness,annealing temperature and annealing time on the surface morphology,crystal structure and photoelectric properties of the films were studied.The results showed that when the Ag layer was 5 nm thick,the annealing temperature was 300?and the annealing time was 20 min,Ag was transformed into silver nanoparticles and gathered inside of the groove during dewetting process.Average transmittance and sheet resistance of the film was 78.40%and 8.21?/sq respectively,leading to a figure of merit of 1.07×10-2?-1,suggesting that photoelectric property of the film got further increase compared with original FTO film.3.Films processed by above steps was coated with AZO layer through magnetron sputtering,and then laser annealed was continue to conducted on them by nanosecond pulse laser.The effects of AZO layer thickness,spot overlap rate and scan line overlap rate on the film surface morphology,crystal structure and photoelectric properties were studied.The results showed that the AZO layer can not only reduce the reflectivity of the film,but also increase the scattering by forming the nucleated structure with the silver nanoparticles,further enhancing optical transmittance of the film.When the AZO layer thickness was 10 nm,spot rate was 90%and scan line overlap rate was 80%,grating structure was formed on the surface of the film,the average transmittance increased to 82.67%,the sheet resistance decreased to7.12?/sq,figure of merit arrived at 2.09×10-2?-1,suggesting that photoelectric property of the film is much better than the original FTO film. |
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