Jousselin-Oba Tanguy, Mamada Masashi, Marrot Jérôme, Maignan Antoine, Adachi Chihaya, Yassar Abderrahim, Frigoli Michel
UMR CNRS 8180 , UVSQ, Institut Lavoisier de Versailles, Université Paris-Saclay , 45 Avenue des Etats-Unis , 78035 Versailles Cedex , France.
Center for Organic Photonics and Electronics Research (OPERA), JST ERATO Adachi Molecular Exciton Engineering Project, and Education Center for Global Leaders in Molecular System for Devices , Kyushu University , Nishi , Fukuoka 819-0395 , Japan.
J Am Chem Soc. 2019 Jun 12;141(23):9373-9381. doi: 10.1021/jacs.9b03488. Epub 2019 Jun 3.
Designing stable open-shell organic materials through the modifications of the π-topology of molecular organic semiconductors has recently attracted considerable attention. However, their uses as an active layer in organic field-effect transistors (OFETs) are very limited, and the obtained hole and electron charge mobilities are around 10 cm V s. Herein, we disclose the synthesis of two peri-fused materials, so-called tetracenotetracene (TT) and pentacenopentacene (PP), which have low band gaps of 1.79 and 1.42 eV, respectively. Their ground state natures have been investigated by different experiments including steady state absorption, electron spin resonance, superconducting quantum interfering device, and variable-temperature NMR along with DFT calculations. TT and PP have closed-shell and singlet open-shell structures in their ground state, respectively, and possess high stability. Their biradical characteristics were found to be 0.50 and 0.64. The origin of the open-shell character of PP is related to the concomitant opening of two tetracenes with the recovering of two extra aromatic sextets and a small HOMO-LUMO energy gap (gap <1.5 eV). Thanks to the high stability, thin film OFET devices could be fabricated. In TG-BC configuration PP shows a remarkably high hole mobility of 1.4 cm V s, while TT exhibits a hole mobility of 0.77 cm V s. In the configuration of BG-TC, ambipolar behaviors for both were obtained with hole and electron mobilities of 0.21 and 0.01 cm V s for PP and 0.14 and 0.006 cm V s for TT.
通过修饰分子有机半导体的π拓扑结构来设计稳定的开壳层有机材料，近来已引起了广泛关注。然而，它们作为有机场效应晶体管（OFET）有源层的应用非常有限，所获得的空穴和电子电荷迁移率约为10 cm² V⁻¹ s⁻¹。在此，我们报道了两种周边稠合材料的合成，即所谓的并四苯并四苯（TT）和并五苯并五苯（PP），它们的带隙分别低至1.79和1.42 eV。通过包括稳态吸收、电子自旋共振、超导量子干涉装置以及变温核磁共振等不同实验，并结合密度泛函理论计算，对它们的基态性质进行了研究。TT和PP在基态分别具有闭壳层和单重态开壳层结构，并且具有高稳定性。发现它们的双自由基特征分别为0.50和0.64。PP开壳层特征的起源与两个并四苯的同时打开以及两个额外芳香六重态的恢复和较小的HOMO-LUMO能隙（能隙<1.5 eV）有关。由于具有高稳定性，可以制备薄膜OFET器件。在TG-BC配置中，PP显示出高达1.4 cm² V⁻¹ s⁻¹的空穴迁移率，而TT的空穴迁移率为0.77 cm² V⁻¹ s⁻¹。在BG-TC配置中，两者均表现出双极性行为，PP的空穴和电子迁移率分别为0.21和0.01 cm² V⁻¹ s⁻¹，TT的空穴和电子迁移率分别为0.14和0.006 cm² V⁻¹ s⁻¹。
