摘要
为了改善聚芴的载流子注入特性,采用密度泛函理论B3LYP/6-31G*方法计算比较了芴、芴-联吡啶和芴-菲咯啉低聚物的几何结构、电子结构、最低激发能及重组能等,并外推到相应聚合物.结果发现:联吡啶/菲咯啉含氮芳杂环的缺电子性质能够诱导聚芴的最高占据轨道(HOMO)和最低空轨道(LUMO)能级分别下降0.45/0.47eV和0.32/0.38eV,提高电子注入能力的同时,调控载流子注入平衡;联吡啶单元的引入导致电子和空穴重组能升高(降低聚芴的载流子迁移率),而芴-菲咯啉共聚物显示了与聚芴相似的迁移性能.
To improve the carrier-injection of polyfluorene,oligomers of polyfluorene,fluorene-bipyridine,and fluorene-phenanthrolin copolymers were theoretically studied for their geometries,electronic structures,excitation energies,and reorganization energies by density functional theory at the B3LYP/6-31G＊ level.We evaluated the properties of the corresponding polymers by linear extrapolation.We found a large decrease of about 0.45/0.47 eV and 0.32/0.38 eV for the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） levels,respectively,after the introduction of electron-deficient bipyridine/phenanthrolin into polyfluorene.These molecules improved the electron injection ability and the balance of carrier-injection in polyfluorene systems.Additionally,the reorganization energy increased for both electron and hole transports upon the incorporation of bipyridine,which resulted in worse carrier mobility.However,the fluorene-phenanthrolin copolymer showed a similar charge transport property to polyfluorene.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2010年第9期2529-2534,共6页
Acta Physico-Chimica Sinica
基金
国家重点基础研究发展规划项目(973)(2009CB623605)
国家自然科学基金(20834006
20774034)资助~~
关键词
聚芴
联吡啶
菲咯啉
载流子注入
量子化学
Polyfluorene
Bipyridine
Phenanthrolin
Carrier-injection
Quantum chemistry
