The Study of the Photo-efficiency of Dye-sensitized Solar Cells by the Modification of Working Electrodes with Graphene

• Main Authors: WANG, JHIH-YI, 王芝貽
• Other Authors: YANG, CHONG-GUANG
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/z9tnw2

碩士 === 國立臺北科技大學 === 化學工程與生物科技系化學工程碩士班 === 107 === In this study, the working electrodes of dye-sensitized solar cells were prepared by screen printing method, and the purpose of this study is to discuss the effect of dye- sensitized solar cells by the modification of working electrodes with different materials and scattering layers. We took X-ray diffraction analyzer (XRD), Raman spectroscopy (Raman) and field emission scanning electron microscopy (FE-SEM) for analysis and identification of the materials. The amount of dye adsorption was measured by UV/Vis spectrometer, and the performance was analyzed by photoelectric conversion efficiency analysis (I-V), incident photon-to-electron conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). Based on the data of I-V, we could know that graphene played the role of the path of electron transmission, reducing the back reaction and increasing the amount of dye absorption, which increases the efficiency of graphene from 6.242% to 6.725%. Although the addition of appropriate amount of polyimide made the short circuit current decrease slightly, the open circuit voltage, FF value and efficiency were obviously improved. Because the missing current was reduced, the efficiency can reach to 7.086%. At last, the sample with the appropriate amount of graphene and polyimide achieved the maximum efficiency of 8.170%. From the results of EIS, it showed that the R2 impedance significantly reduced for adding graphene and polyimide, indicating that graphene played the role of the electron transport path to make electrons more easily transportable. Besides, polyimide could reduce the back reaction. Adding a scattering layer could also reduce the R2 impedance. It was speculated that the effective use of photons increased the short circuit current density and the excitation electron transition to the working electrode conduction band to facilitate electron transport. Finally, the best performance of the sample was achieved by mixing the appropriate amount of graphene and polyimide.