Sensitive Film Water Adsorption Process And Its Effect On Solar Cell Performance

Dye-sensitized solar cell(DSC),as a new type of solar cell,has received extensive attention due to its advantages such as simple preparation,high photoelectric conversion efficiency,and low price.The DSC device consists of a layered structure composed of a photoanode,an electrode solution and a counter electrode.The photoanode is composed of a layer of light-responsive dye molecules adsorbed on the surface of the nano-semiconductor film,that is,the dye-sensitized film.During the preparation process,the dye-sensitized film is inevitably exposed to air with a certain humidity,and the moisture in the air will be easily adsorbed on the film surface.Aqueous sensitized film will have an important impact on battery performance.Unfortunately,the process of the dye-sensitized film adsorbing water and its effect on battery performance are still unclear.Therefore,in this paper,the quality of the dye-sensitized film adsorbed water was studied in-situ with the help of quartz microbalance(QCM),and the effect of the aqueous sensitized film on the photovoltaic conversion performance of the battery was also studied.The main work is carried out from the following aspects:First,based on the QCM in-situ test technology to study the mass response of N719 sensitized nano-TiO₂ film when exposed to air with constant humidity.By changing the humidity and the dye distribution on the surface of the nano-film,a mathematical model was established to obtain the mechanism of the sensitized film's adsorption of water molecules.Secondly,based on the QCM test technology,the mass response of the N719sensitized film in contact with a certain p H aqueous solution was studied.By changing the p H value of the aqueous solution,the kinetic constants of dye desorption of the sensitized film in the aqueous solution are obtained.The empirical formula between the p H value in the aqueous solution and the desorption kinetics is obtained by software fitting.Thirdly,the effect of the sensitized film exposed to constant humidity on the battery performance was studied.By changing the conditions such as relative humidity and different storage time,the photovoltaic performance of the battery was monitored in real time,and the effect mechanism of the sensitized films with different water content on the photovoltaic performance of the battery was obtained.The influence mechanism of different water-sensitized films on the internal impedance of the battery was extracted and analyzed.Finally,the effect of the sensitized film exposed to variable humidity on battery performance was studied.By changing the order of relative humidity and other conditions,the sensitized film is dehydrated and reabsorbed.The effect of dehydration or re-absorption process on the photovoltaic performance of the battery was studied.The ultraviolet-visible absorption spectroscopy(UV-vis)and infrared spectroscopy(ATR-FTIR)were used to study the electronic transitions and dye molecular chemical bonds of the sensitized film during dehydration and water absorption.The impact of other states.The research of this project has certain theoretical and practical significance for the water absorption mechanism of nano-films,the synthesis of dye molecules,the stability of battery devices,and the preparation process,storage and transportation in the future market production process.