Study On The Diffusion Of Gel Electrolyte Of DSSC By PFG NMR And Synthesis Of PSC As The New Materials For Hole Transport

There are two parts in this thesis:firstly, we use pulsed field gradient NMR (PFG NMR) diffusion to achieve quantitative measurement of diffusion coefficient of dye-sensitized solar cell (DSSC) in the gel electrolyte; and then a new hole transport material (HTM) for perovskite solar cell (PSC) is synthesized and characterized in the second part. Details are as follows:We prepared a serious of poly (methyl methacrylate - butyl acrylate - methacrylic acid)/ polyethylene glycol/sodium iodide/iodine/γ-butyrolactone [P (MMA-BA-MAA)/PEG/ NaI/I2/GBL] gel electrolyte with different ratio. Then by use of control variables method, we had measured the diffusion coefficient of small molecular gel electrolyte of GBL in the Macromolecules skeleton. And the relationship between the diffusion coefficient and cell efficiency between small molecules GBL in terms of the solid content of the gel-forming intermolecular hydrogen bonds, as well as the content of electrolyte ions cooperation between envelope and so on, were furtherly studied. The conclusion were as follows:The impact of solid content on gel formation and intermolecular hydrogen bonds:When synthesized a series of different proportions of P (MMA-BA-MAA)/PEG polymer formulated as a gel electrolyte with different MAA content, the polymer quality needed to prepare gel electrolyte varied with different MAA content. The lower MAA content, the more quality. the resistance that redox couples and liquid electrolyte in the macromolecules is larger, and the diffusion coefficient and cell efficiencies are low. With the growth of MAA content, the diffusion coefficient and the efficiency of the battery has a maximum value; when it exceeds this maximum, with the further growth of MAA content, hydrogen bonding plays a dominant role at this time, thereby reducing the macromolecular skeleton free volume, reducing the diffusion efficiency and lowering cell efficiency.The impact of complexation of ionic bond:during the experiment, we compared the effects of mainly sodium and potassium salts of the cell efficiency and diffusion coefficients. When the same content of sodium and potassium salts were added, by measuring the results of NMR PFG, we obtain the diffusion coefficient of sodium than potassium large, mainly due to the complexation between potassium and stronger than the polymer sodium salt, which results in reduced free volume of the matrix macromolecules, and the small molecular diffusion resistance increases suffered.The impact of electrolyte content:In the P (MMA-BA-MAA)/PEG configured as a gel electrolyte system, we measured the effects of different NaI/I2 of NMR PFG diffusion coefficient, and the results show that the diffusion coefficient has little effect when NaI:I2 is low, but a greater impact on cell efficiency. The main reason is that when the sodium content is very low, less sodium and interaction between polymers, impacts of the polymer skeleton is small, and little change of free volume, so little effect on the diffusion coefficient; but because of its redox electrons less, so the composition of the battery circuit current generated in less dense, so that the cell efficiency is low.In the second portion, a new kind of solar cells perovskite hole transport material (2,6-bis triphenylamine 4,8-bis (alkoxy) benzo [1,2-B:4,5-B’] dithiophene) was synthesized by the use of 2,6-dibromo-4,8-bis (alkoxy) benzo [1,2-B:4,5-B’] dithiophene and 4- three aniline as the starting material by SUZUKI reaction. And the elemental analysis and nuclear magnetic resonance spectroscopy (NMR) results show that we got the right product; and thermal gravimetric analysis (TGA) show that the material start to decompose at 280℃,which means that it has good thermal stability; by the combination of cyclic voltammetry (CV) and UV methods to characterize its electrical properties, which can draw a band gap of 2.63 eV, HOMO energy level were -5.33 eV and -5.31 eV.