Study On The Synthesis And Properties Of Fullerene Derivative Electron Transport Functional Materials

As a typical n-type electronic transport materials,C₆₀ derivatives are widely used in OFET, polymer thin-film solar cell and so on.Especially in polymer thin-film solar cell,they have a good energy level matching with the electron donor polymer P3HT or MEH-PPV.However, C₆₀ has a poor solubility in organic solvents which greatly affects their applications in polymer thin-film solar cell.On the other hand,the LUMO energy of C₆₀ is relatively low vulnerable to the attack of oxygen and water in air so that the organic field-effect transistor based on these compounds are unstable in the air.Therefore,we will develop a series of C₆₀ derivatives with good solubility and stability in air as electronic transport materials.In this work,two new methanofullerenes with perfluoroalkyl groups have been designed and synthesized.The optical,electrochemistry,quantum chemistry and OFET properties have been studied.The electrochemistry properties of compound A11 and A12 show that they have low LUMO energy and the LUMO energy of compound A11 is lower than that of PCBM which indicates that it has better electron-acceptting ability.Meanwhile,we successfully prepared OFET based on them at two different bottom temperature and studied their device character.The charge mobility and the open circuit voltage of A11 respectively reaches as high as 6.7×10^-2 cm²/V·s and 5×10⁷ V.Therefore,we conclude that the electron-acceptting ability of compound increases with the introducing of perfluoroalkyl.Two new methanofullerenes both with perfluoroalkyl and alkyl groups have been designed and synthesized.The optical and electrochemistry characteristics have been studied. These two compunds have good solubility and can effectively quench the fluorescene of PPV. They have low LUMO energy as PCBM indicating their good electron-acceptting ability. Meanwhile,the polymer thin-film solar cell characteistics show that Isc and PCE of B12 respectively is 11.37 mA/cm² and 3.42%which are higher than those of PCBM.A series of new C₆₀ derivatives C4-C7 with different length of alkyl have been designed and synthesized.They have perfect solubility in organic solvents and low LUMO energy similar to that of PCBM.Therefore,they are good n-type materials potential for application in OFETs and polymer thin-film solar cells.