Preparation Of Laser-induced Graphene Electrodes And Their Application In Dye-sensitized Solar Cells

Dye-sensitized solar cell（DSSC）is an efficient and low-cost solar cells in the third generation photovoltaic devices.Precious metal Pt,as the traditional electrode material,has excellent catalytic performance and stability.However,the drawbacks of high-cost and corrosion in the electrolyte limit their large-scale application.Therefore,it is necessary to find cost-effective alternative materials with highly catalytic performance.Laser induced graphene（LIG）has the advantages of high electrical conductivity,high specific surface area,and the environment-friendly fabrication process.Nowadays,LIG materials are mostly used in supercapacitors and energy storage devices,but seldom applied in solar cells.In this thesis,LIG materials are prepared by laser-scribing different polymer materials,and applied in DSSC.The main research contents and results are as follows:（1）Laser induced graphene counter electrodes from PEDOT:PSS film:at room temperature,the PEDOT:PSS films were prepared by drop-coating method.Different laser powers were used to obtain various LIG materials.After laser treatment,the catalytic performance were increased.The DSSCs test results show that the LIG counter electrode prepared by the relative laser power 70%achieved the good performance,and it exhibits the best catalytic property,and its photoelectric conversion efficiency（PCE）is the best of 3.66%,reaching 82%of the DSSC based on Pt counter electrode（4.47%）.（2）Laser induced graphene counter electrodes from polyimide（PI）film:the PI film was pasted on glass and different laser powers were applied to obtain different LIG materials at room temperature,the analysis show that the LIG electrodes have good electrical conductivity and catalytic property.Through the comparative analysis,the approximate optimal laser power was obtained.The DSSCs test results show that the LIG counter electrode prepared by the relative laser power 100%exhibits the best catalytic property,and its PCE is the best of 3.56%,reaching 83%of the DSSC based on Pt counter electrode.（3）Laser induced graphene/Pt composite counter electrodes:the H₂Pt Cl₆ layer was prepare by drop-casting different concentration of H₂Pt Cl₆ solution on PI film at room temperature,the H₂Pt Cl₆/PI films were irradiated by laser with the optimal power in the previous chapter to obtain the Pt/LIG composite electrodes with different Pt contents.These composite electrodes have good conductivity.The photovoltaic performance of the DSSCs show that among three concentrations the Pt/LIG composite electrode fabricate from 5 m M H₂Pt Cl₆ solution exhibits the best PCE of 3.80%,which is 89%of the reference DSSC based on pure Pt electrode（4.29%）and higher than that of LIG electrode derived from pristine PI film.