Preparation Of Water-alcohol Soluble Tin Oxide And Its Application In New Type Solar Cells

Solar energy plays an important role in new energy because of its easy to use and abundant reserves.Tin oxide is an excellent and cheap electron transport material.Its low cost,wide band gap,low energy level and low processing temperature make it very competitive.In this paper,we explore the preparation process of tin.oxide electron transport layer with high performance for different types of organic solar devices based on different solvents and at low temperature.The fabricated tin oxide electron transport layer avoids the problem of interface carrier recombination to a great extent.1.Tin oxide hydrosol is prepared and used in the electronic transmission layer of reverse organic solar cell.The crystal properties,functional groups and particle size distribution of tin oxide nanoparticles were characterized by X-ray diffraction,Fourier infrared spectroscopy and dynamic light scattering.The element composition and valence state of tin oxide electronic transmission layer are analyzed by X-ray photoelectron spectroscopy.The energy level of tin oxide electronic transmission layer is analyzed by UV electron energy spectrum,and the photovoltaic performance of devices based on tin oxide electronic transmission layer is analyzed by J-V test.Tin oxide nanoparticles can be evenly dispersed in alkaline water system,and potassium ions in the system can passivate the interface of tin oxide electron transport layer.Low pH value is not conducive to the deprotonation of SnO2 nanoparticles,which is unfavorable to the coating of potassium ions.The lack of potassium ion is not conducive to the passivation of tin oxide electron transport layer interface.The higher pH value is beneficial to the distribution of potassium ions in the solvent water,and is also not conducive to the coating of potassium.ions on the surface of SnO2 nanoparticles.Therefore,adjusting the appropriate pH value is related to the success of interface passivation.In addition,the tin oxide electron transport layer annealed at low temperature(60℃)also has certain crystallization properties,but the stronger annealing conditions have no significant effect on the crystallization properties of tin oxide electron transport layer.Based on the suitable pH value(pH=9.7),the content of potassium in tin oxide electron transport layer can reach 4.43 at.%,the device efficiency can reach 15.54%.The maximal efficiency of the device via strong annealing is 15.10%.2.Tin oxide alcohol sol was prepared and used as electron transport layer of forward organic solar cells.The crystalline properties,functional group properties and particle size distribution of SnO2 nanoparticles were characterized by X-ray diffraction;Fourier transform infrared spectroscopy and dynamic light scattering.The element composition and valence properties of tin oxide electron transport layer were analyzed by X-ray photoelectron spectroscopy,and the photovoltaic performance of devices based on tin oxide electron transport layer was analyzed by J-V test.Spincoating alkali solution directly on the surface of tin oxide electron transport layer is not conducive to obtain high efficiency electron transport layer.Because the alkali solution used in spin coating contains a lot of hydroxyl ions,it will limit the passivation effect of positive ions on the interface.Dispersing tin oxide hydrosol directly in alcohols is not conducive to obtaining stable tin oxide hydrosol.So we spin dry the tin oxide hydrosol and redisperse it in alcohols.Appropriate amount of KOH was added to make it have good interface passivation.T he efficiency of the device is similar to that of the standard part.When the amount of KOH is 10%,the tin oxide electron transport layer has a good interface passivation.The short-circuit current density of the device can reach 25.95 m A cm-2,the open-circuit voltage can reach 0.82 V,and the fill factor can reach 72.54%.The highest device efficiency can reach 15.38%.