Magnetron Sputtering Combined With Liquid Phase Method To Prepare Perovskite Solar Cells And Their Performance Research

At present,perovskite solar cells(PSC)are one of the most important research topics in the field of photovoltaic.After ten years of development,the photoelectric conversion efficiency(PCE)of PSC has been increased from the 3.8%to 23.3%.In addition,the perovskite materials is widely available and the film can be prepared by solution process.These advantages make the organic-inorganic lead-halide perovskite the most promising photovoltaic materials.TiO2 is the most widely used electron transport material for PSC.However,TiO2 has a low electron mobility and poor ultraviolet stability,so TiO2 is not an ideal material.The electron mobility of SnO2 is two orders of magnitude higher than that of TiO2.The w:ider band gap makes the SnO2 electron transport layer(ETL)have better hole blocking ability,inhibiting the recombination between electrons and holes.The wider band gap can also avoid the absorption of high energy photons thereby reducing the loss of current.The most commonly used method for preparing each layers of PSC is spin coating.Although this method is simple and can be proceeded under mild conditions,the active area of these devices is small and the preparation process of the film with poor repeatability is not easy to control,which hinders the commercialization of PSC.In my dissertation,the following researches are carried out based on two aspects of PSC mentioned above:(1)The SnO2 ETL of PSC is prepared by magnetron sputtering.In this part,the optimal annealing temperature of SnO2 film was investigated.It was found that SnO2 film has good crystallinity and surface roughness after 200 ℃ annealing process in vacuum tube furnace,ensuring both electron transport capacity and smooth surface of film.(2)The perovskite film(CH3NH3PbI3)was prepared by magnetron sputtering and spin-coating method.Firstly,the PbO film was prepared by magnetron sputtering and then the substrate was immersed in CH3NH3I solution.During the soaking process,the surface of the substrate was gradually turned black.After the immersion,the film was placed in a vacuum tube furnace and annealed under 100°C.After annealing process,a perovskite light absorbing layer with a flat surface and a large area was prepared.(3)The SnO2 ETL prepared by magnetron sputtering and the perovskite film prepared by magnetron sputtering and spin-coating method were used to assemble the PSC,spiro-OMeTAD was employed as the hole transport layer and Au as the metal counter electrode.The performance of PSC with different ETL and fabricating method is compared.The results show that PSC with TiO2 ETL has a higher open circuit voltage compared to that with SnO2,but the short circuit current density of TiO2-based device is significantly lower than SnO2-based device.After the replacement of ETL,the PCE was increased from 10.12%to 10.89%.On the basis of SnO2 ETL,the perovskite film prepared by magnetron sputtering and spin-coating method was introduced into the PSC,the PCE decreased from 10.89%to 8.70%,but the active area of device is significantly increased from 0.12 cm2 to 0.9 cm2.