Synthesis Of Porphyrin Derivatives And Their Application As Photovoltaic Materials

As a new kind of functional organic materials, porphyrin derivatives are getting a large amount of attention due to their excellent optical and electrical properties. Porphyrins have been used as photosensitizer in dye-sensitized cells for many years. In order to develop new properties and expand new application of porphyrins especially in the heterojunction solar cells,4new porphyrin derivatives-tetraphenylporphyrin(TPP),5,10,15,20-tetra-(hydroxyllp-henyl)porphyrin(THPP),5,10,15,20-tetra-(4-carboxyphenyl)porphyrin(TCPP) and5,10,15,20-tetra-(4-carbomethoxyphenyl) porphyrin(TCMPP)-were designed and synthesized. These porphyrins were charactered by MS,1HNMR and IR. Their optical and electrical properties were analyzed. Their potential applications in solar cell were investigated and the optima-zation of devices were researched.The photophysical and electrochemical properties of these symmetric tetra-substituted porphyrins were studied according to UV-vis absorption spectra, fluorescence spectra and cyclic voltammetry, based on which the relationship between molecular structure and optical, electrical properties were linked.The photovoltaic properties of TPP, THPP, TCPP and TCMPP were studied. The organic photovoltaic devices were fabricated as follows:ITO/Porphyrins/PTCDA/Al. The power conversion efficiency of photovoltaic cells of TPP, THPP, TCPP and TCMPP were0.11%,0.15%,0.39%and0.02%respectively.The optimizations of the organic photovoltaic devices were analyzed. For porphyrins which can form the hydrogen bond with PTCDA, such as THPP and TCPP, the annealing has been adopted and the optimal temperature has been determined. After the annealing process, the power conversion efficiency of photovoltaic cells of THPP and TCPP increased by150%and220%repectively.