Fabrication And Performance Investigation Of Flexible Quantum Dot Sensitized Solar Cells Materials

Due to tremendous consumption of traditional energy and the increasing global population,it is necessary to develop clean and renewable energy.Among numerous clean,renewable energy sources discovered,solar energy is the most promising and perfect answer to the energy problem.Because of its low environmental impact and being one of the most environment-friendly and easy-to-produce energy sources,solar cell technology has evolved rapidly in recent years.Quantum dot-sensitized solar cells(QDSSCs)are one of the research hotspots of the new-generation solar cells,and many important research achievements have been made.However,the application of QDSSCs in flexible devices is facing lots of problems,such as performance is still far below expectations,poor stability,low transparency,etc.Lots of researchers have been focused on reducing the thickness of the Ti O₂films to improve the transparency and flexibility of the QDSSCs,which normally cause the reduction of power conversion efficiency.To solve this issue,in this study,a simple process of preparing transparent Ti O₂films as the photoanodes of QDSSCs is presented,and the effect of the film thickness on the performance of QDSSCs is explored.Finally,based on the process,flexible and transparent Ti O₂photoanodes and flexible counter electrodes are fabricated and assembled into flexible QDSSCs,and photoelectric performances and stability of the devices are studied.The main research contents and results are as follows:(1)Different TiO₂nanoparticles(P25,rutile,anatase)were dispersed into N-butyl titanate solution and spin-coated on FTO glass.The as-prepared Ti O₂films were used as photoanodes and the performances of QDSSCs were investigated.It has been shown that QDSSCs assembled by Ti O₂film prepared from N-butyl titanate and P25 Ti O₂slurry achieved the best PCE 2.70%.Appropriate Ti O₂film thickness and different crystal Ti O₂have important influence on the performance of QDSSCs.QDSSCs assembled with transparent NTP TiO₂films as photoanodes material showed excellent performance.(2)P25 TiO₂was mixed with N-butyl titanate as a precursor solution,and the solution was rotated onto ITO-PET in three layers.Flexible transparent Ti O₂thin films were prepared by low temperature annealing at different temperatures.After sensitization,photoanodes were formed and semi-flexible QDSSCs with good performance were assembled.The effect of annealing temperature on the performance of QDSSCs was investigated under AM1.5 illumination.The device prepared by annealing flexible transparent TiO₂thin film at 80?has the best performance with PCE of 2.10%.(3)The flexible CuS counter electrode was prepared using ITO-PET as the substrate,and then vulcanized after copper plating.The flexible quantum dot sensitized solar cells(FQDSSCs)were assembled with the flexible photoanode,and their performance was tested.The influence of bending conditions on the performance of FQDSSCs was explored.The electrocatalytic activity and stability of Cu S versus Cu S/FTO were studied and compared.The prepared FQDSSCs have high photoelectric performance,electrochemical performance and stability.