Study On The Construction And Photoelectrical Properties Of Sandwich Structure Thin Films Of AZO/Ag NWs/AZO

The transparent conductive oxide is widely used as transparent conductive electrode in many photoelectric devices such as liquid crystal display, thin film solar cells and organic light-emitting diodes. Zinc oxide thin films have a better transmittance in the visible range and higher exciton recombination energy and are stable existence in the plasma of hydrogen. Furthermore It can greatly improve the electrical properties when mixing a small amount of Al, Ga in the zinc oxide thin films. Moreover, AZO thin films have the advantages of cheap and relative rich resources. Thus, AZO transparent conductive thin films are ideal materials to replace ITO and FTO. To further improve the photoelectric properties of AZO thin film, preparing sandwich structure of AZO/Ag NWs/AZO thin films is an effective method. The middle-layer of sandwich structure was major prepared by spin coating in the the literature, but the spin coating method will result in the loss of silver nanowires and the film is not uniform in the process of prepare nano-silver film. Therefore, seeking a way to avoid losses, reduce costs is very important. Vacuum filtration method can make silver nanowires falls on the membrane at a constant rate during the preparation of nano-silver thin film, this way make the silver nanowires disperse evenly on the membrane and avoid the loss of silver nanowires to a certain extent. So combine the nano-silver film with AZO thin films which prepared by vacuum filtration and magnetron sputtering to build AZO/Ag NWs/AZO sandwich structure thin films is an effective way to optimize the photoelectric of AZO thin films.In this study, we first prepared the AZO thin films on the glass substrate through the ratio frequency magnetron sputtering Method. By adjusting the various parameters such as sputtering power, sputtering pressure and the distance between the target and substrate, we obtained good performance of AZO thin films. But in the process of study, we found that the transparency and the conductivity of the film could not reach the optimum value at the same time. Therefore, we introduced the high conductivity silver nanowires into the AZO thin films which have a good transmittance to prepared such a multiply structure Ag NWs/AZO, AZO/Ag NWs/AZO. The results showed that the conductivity of AZO thin film was greatly improved after introducing the conductive silver nanowires and we obtained good transparency conductive electrode which have better light transmittance and conductivity by this way.The main content of the paper summarized as follows:1?Prepared of AZO thin films by ratio frequency magnetron sputtering method.By adjusting the sputtering power, sputtering pressure and the distance between target and substrate, we prepared of AZO thin films which have good performance without heating substrate. The research found that the distance between target and substrate have great influence on the performance of the film. With increasing of distance between the target and substrate, the film showed a significant(002) diffraction peak which had a hexagonal structure. Also, the films have good C-axis orientation and grow perpendicular to the substrate. The intensity of X-ray diffraction peak?the particle size and the rate of sputtering increased with the distance gradually decreased, while the FWHM and internal stress decreases with the distance gradually decreased. Finally, we obtained the AZO thin film which the transmittance and the sheet resistance gradually reduced with the increasing of the distance between target and substrate. By adjusting the distance between the target and substrate, we obtained a good performance of AZO thin films that have high transmittance of 89.56% and sheet resistance of 44.4 ?/sq.2?Prepared of the multilayer structure of AZO/Ag NWs/AZO transparent conductive thin filmBased on the previous work, we found that the light transmittance and sheet resistance of AZO thin film could not reach the optimum value at the same time. Therefore, we introduced the high conductive silver nanowires into the AZO films to improve the electrical properties of AZO thin film when the film was thin enough that have good transmittance. First, we synthesized silver nanowires by polyol reduction methods that the silver nanowires have high aspect ratio. Then, prepared of nano-silver membrane by vacuum filtration method, Finally, we combined the AZO thin film with nano-silver membrane to built a multilayer structure such as Ag NWs/AZO, AZO/Ag NWs/AZO on different substrates. The photoelectric properties and the morphology of multilayer structure was characterized by UV spectrophotometer, four-point probe system and scanning electron microscope. The results showed that the silver nanowires greatly increased the conductivity properties of AZO films, the obtained multilayer structure of thin films which have the transmittance of 82.76% and the sheet resistance as low as 32.4 ?/sq. Finally, we applied the sandwich structure to the CuZnSn(S,Se) solar cells that the solar cells have the efficiency as high as 4.67%.