Self-assembly And Optoelectronic Applications Of Two Porphyrin Triamides

The supramolecular system formed by self-assembly of molecules which owns a con-jugated largeπbond is expected to enhance the photoelectron transmission efficiency through its long range order structure,thereby obtaining a long-term application in the field of optoelectronics.In this paper,two porphyrin trimer molecules R1,R2 based on trimesoyl chloride were designed and synthesized.The self-assembly behavior of two molecules in different solutions was studied,and the molecules were further applied to optoelectronic devicesThe porphyrin was synthesized from methyldipyrrolidine,4-nitrophenyldipyrrolidine and p-dodecyloxybenzaldehyde by the Mac Donald 2+2 method,and then reduced by stan-nous chloride,and with benzotriene.The acid chloride undergoes a nucleophilic substitution reaction,and finally reacts with the zinc salt to finally obtain two trimer molecules,R1 and R2.The reaction intermediates and target molecules were characterized by MALDI-TOF and NMR.UV-visible absorption spectroscopy was used to study the self-assembly behav-ior of R1 and R2.It was found that R1 existed in a single molecule state in a good solvent such as chloroform and tetrahydrofuran.In poor solvent,R1 showed self-assembly behavior at a proper concentration and the critical concentration of R1 is 1×10^-6 mol/L.R1,R2 were applied as photosensitizers to the DSSC device.The photovoltaic perfor-mance of DSSC based on R1,R2 self-assembly system is discussed.It is predicted that the formation of a good electron transport system due to supramolecular self-assembly behavior can effectively improve the photoelectric conversion efficiency.However,due to the poor solubility of R2,the expected effect was not obtained.Meanwhile,it was found that the DSSC sensitized in the cyclohexane solution exhibited greater electron complex resistance and higher electron lifetime.The photovoltaic performance of R2,TBA-S-CN co-sensitized solar cells was ex-plored.Combined with the J-V curve and Bode plot of the common sensitization system,co-sensitization can effectively prevent the dark current generation of DSSC and increase the open circuit voltage,but due to the larger molecular structure of R2,the dye adsorption is reduced,resulting in lower photoelectric conversion efficiency.The potential application of R1 as an organic semiconductor material in organic field effect transistors was investigated.The results show that R1 has high thermal stability and the energy level matches the metal work function.However,due to its poor film formation in solution,it is necessary to further study the film formation method.