The Research Of Dye-Sensitized Solar Cells Based On Laser-Induced Graphene Counter Electrodes

Environmental issue and rising energy requirement have urged the conversion of energy systems,and therefore,the research on clean and sustainable energy becomes increasingly important.Solar energy is one of the promising renewable energy resources with abundant availability.The investigation and application in the area of photovoltaic devices have become the focus of studying and have been continuously making progress.As the third generation of photovoltaic devices,dye-sensitized solar cells(DSSCs)have good development prospects owing to simple preparation process,low cost raw material,rich resources and environmental friendliness.The traditional precious metal,platinum(Pt),has become the primary choice for electrode materials because of its excellent performance.However,its reserves are scarce and the price is highly expensive,resulting in the difficulty of achieving industrial production.Therefore,it is an important research direction to explore economical and practical alternative materials with good catalytic activity.Laser induced graphene(LIG)prepared by the laser induced method using various carbon resources has rapidly developed in recent years.The laser induced method is accurate,efficient and pollution-free.The obtained LIG has three-dimensional porous structure with high specific surface area and excellent catalytic performance.LIG is often used in sensors and energy storage devices,but rarely in solar cells.In this paper,different polymers are transformed into LIG by the laser induced method,and their performance as DSSC counter electrode materials in DSSCs was explored.The specific research contents and results are as follows:(1)The LIG counter electrode prepared by laser inducing poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/dimethyl sulfoxide(PEDOT:PSS/DMSO): The PEDOT:PSS/DMSO film was prepared by drop-casting method and dried in ambient air.Then,the LIG counter electrode material was obtained by laser induction with different laser powers.After laser treatment,the surface morphology changed and the catalytic activity improved.The device test results show that the LIG counter electrode treated with relative laser power of 70% exhibits the highest photoelectric conversion efficiency(3.26%),which is 73% of that of platinum counter electrode(4.44%),providing promising outcomes.(2)The LIG counter electrode prepared by laser inducing polyimide film: The polyimide film was synthesized using the thermoplastic polyimide solution on FTO glass by doctor-blading method and a certain heating process.Then,the LIG counter electrode material was fabricated by laser treatment with different numbers of times,demonstrating good catalytic activity.The effect of laser treatment times on its structure and electrochemical properties was investigated using various characterization and testing methods.The device testing results indicate that the LIG prepared with a laser treatment frequency of three times exhibits the best catalytic performance,with a photoelectric conversion efficiency of 4.78% as a counter electrode for DSSC,which is 90% of that of the platinum counter electrode(5.31%).(3)The LIG/Carbon cloth composite counter electrode: The carbon cloth was firstly fixed on the glass substrate,and the counter electrode was prepared by doctor-blading and drop-casting methods.PEDOT:PSS/DMSO was drop-cast onto the carbon cloth,and treated with a 70%relative laser power.The thermoplastic polyimide solution was prepared using the doctor-blade method to form a composite film on the carbon cloth,which was then treated with a 100% laser power for three times.Two types of composite counter electrode materials were obtained and their photovoltaic properties were investigated.The device testing results indicate that the PEDOT:PSS-based LIG composite counter electrode has a higher photoelectric conversion efficiency than the polyimide-based LIG electrode.