Effects of Conformation on Doping Efficiency in π-Extended Bipyranylidene Molecules: Relationship between Molecular Structure and Electron-Doping Ability for Developing n-Type Organic Thermoelectrics
作者:Takaya Matsuo、Kohsuke Kawabata、Kazuo Takimiya
DOI:10.1246/bcsj.20220124
日期:2022.7.15
analyses of 1 and 3 elucidated that 3 has a totally planar π-conjugated structure over the whole molecule, whereas 1 has a non-planar structure. Although the energy levels of the highest occupied molecular orbitals of 1–3 evaluated by the electrochemical measurement in solution were not significantly different, the work function of 3 thin-film evaluated by the Kelvin probe method was slightly higher
电子掺杂是开发n型有机热电材料的必要过程,因此寻找有效的n型掺杂剂至关重要。通过用富含电子的 3,4-乙烯二氧噻吩和2,2'-双(3,4-亚乙基二氧噻吩)部分,我们合成了新的候选分子(分别为2和3)作为 n 型掺杂剂。1和3的单晶 X 射线分析表明,3在整个分子上具有完全平面的 π 共轭结构,而1具有非平面结构。虽然在溶液中通过电化学测量评估的1-3的最高占据分子轨道的能级没有显着差异,但通过开尔文探针法评估的3薄膜的功函数略高于1和2。此外,3能够对n型半导体聚合物聚(苯并咪唑并苯并菲咯啉)(BBL)进行电子掺杂,得到的掺杂BBL显示出良好的热电特性,功率因数为1.25 × 10 -3 μW m -1 K - 2,这比1和2掺杂的 BBL 薄膜高一个数量级。这些结果表明3的高平面度有助于电子掺杂能力,这可能是进一步开发用于有机热电应用的 n 型掺杂剂的有用信息。