| Solar cell is an effective device that converts light energy into electricity directly based on photovoltaic effect.As an important part of solar cell,photoanode has the function of load light absorption and transmission of photogenerated electrons to conductive substrate.TiO2 has been widely used in the photoanode of solar cells due to its high chemical stability,low cost,non-toxicity and environmental protection.Its internal electrical performance and surface performance determine the conversion efficiency of solar cells.At present,a lot of achievements have been made in the research of TiO2 photoanode.However,TiO2 has the disadvantages of wide band gap,narrow light response range and low electron mobility,so how to broaden its light absorption range and reduce its photogenerated carrier recombination rate to improve its electron transport performance is the focus of current attention.In this paper,TiO2 composite oxide ZnO with high electron mobility and semiconductor material Bi2S3 with narrow band gap were used to form a composite structure to improve the photoelectric performance of TiO2 photoanode material.Main research contents and results are as follows:1.Rutile TiO2 nanorods were prepared on FTO conductive glass by hydrothermal method.To optimize the hydrothermal growth time and the concentration of butyl phthalate,the optimal growth time of TiO2 nanorods was determined to be 12 h and the concentration of butyl phthalate was 0.5 mol/L.At this time,TiO2 nanorods have the highest crystallinity and are arranged neatly.On this basis,ZnO nanorods were grown,and the optimal TiO2/ZnO nanorods composite film structure was prepared by regulating the growth time of ZnO.The results showed that the hydrothermal growth time of ZnO had a great influence on its structure morphology.With the increase of the hydrothermal growth time of ZnO,the diameter and density of the nanorods increased.2.On the basis of preparing TiO2 nanorods by hydrothermal method.TiO2/Bi2S3 composite film was prepared by hydrothermal method as photoanode material.The optimal preparation process of TiO2/Bi2S3 composite thin film material was optimized by adjusting the sensitization concentration,sensitization time and annealing temperature of the composite material.The results showed that the sensitization of Bi2S3 narrowed the band gap width of TiO2,caused the red shift of the absorption band edge of TiO2,and increased the photocatalytic activity of TiO2 in the visible light range.With the increase of the concentratio n of Bi2S3,the photoelectric properties of composite materials show a trend of increasing first and then decreasing.When the concentration was 2 mM/L,the photocurrent density reached the maximum value of 0.16 mA/cm2 and the flat band potential was-1.0V.On this basis,the sensitization time of Bi2S3 was changed,and the photoelectric performance of the composite was the best when the reaction time was 6 h.TiO2/Bi2S3 composite structure was prepared and treated with annealing.After annealing,the grain size of Bi2S3 could be effectively increased,so as to improve its light absorption intensity and reduce the composition of photogenic carriers.The optimal annealing temperature is 350? and the annealing time is 40 min.At this time,the current density is the highest and the electron life reaches 85.56 ms.3.On the basis of preparation of TiO2 nanorod by hydrothermal method,Bi(Bi(NO3)3)nitrate,Bi(Bi(CH3COO)3)and Bi(BiCl3)chloride were used as Bi sources to prepare Bi2S3 sensitizing agent,and then TiO2/Bi2S3 composite film materials were prepared by hydrothermal method.The results showed that:when the reaction time was 6 h at 100? and the reaction time was 6 h,the surface structure of Bi2S3 obtained by Bi source in 3 was spherical spiny,short branched and linear in sequence.Its optical performance Bi(CH3COO)3 is the best,while Bi(NO3)3 has better electrical performance. |
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