Multifunctional Benzo[4,5]thieno[3,2‑b]benzofuran Derivative with High Mobility and Luminescent Properties

Development of multifunctional materials and devices has garnered enormous attention in the field of organic optoelectronics; nevertheless, achieving high mobility together with strong luminescence in a single semiconductor remains a major bottleneck. Here, a new multifunctional semiconductor molecule, 2,7-diphenylbenzo­[4,5]­thieno­[3,2-b]­benzofuran (BTBF-DPh), that integrates high charge transporting [1]­benzothieno­[3,2-b]­[1]­benzothiophene with a strongly emissive furan group, is synthesized and applied in three types of optoelectronic devices, including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and organic phototransistors (OPTs). OLEDs based on BTBF-DPh as the emissive layer showed a blue emission with CIE coordinates of (0.151, 0.069) and a maximum current efficiency of 2.96 cd A–1 with an external quantum efficiency of 4.23%. Meanwhile, OFETs fabricated with BTBF-DPh thin film manifested a carrier mobility of 0.181 cm2 V–1 s–1, which is comparable to that of thiophene-based counterparts. Additionally, BTBF-DPh-based OPTs exhibited a maximum responsivity and detectivity of 2.07 × 103 A W–1 and of 5.6 × 1015 Jones, respectively. On the one hand, our rationally designed material, BTBF-DPh, has a dense and close-packed structure with an extended π-conjugation, facilitating charge transport through adjacent molecules. On the other hand, the weakened dipole–dipole interactions between BTBF-DPh molecules that resulted from the unambiguous J-aggregation and reduced spin–orbit coupling caused by replacing sulfur atom significantly suppress the exciton quenching, contributing to the improved photoluminescence performance. These results validate that our newly developed BTBF-DPh is a promising multifunctional organic semiconductor for optoelectronic devices.有机光电子领域中，多功能材料与器件的开发已受到广泛关注。然而，在单一半导体中同时实现高载流子迁移率与强发光性能仍是一大核心瓶颈。本文合成了一种新型多功能半导体分子——2,7-二苯基苯并[4,5]噻吩并[3,2-b]苯并呋喃（BTBF-DPh），其将具备高电荷传输特性的[1]苯并噻吩并[3,2-b][1]苯并噻吩与强发光呋喃基团相结合，并将其应用于三类光电器件，包括有机发光二极管（OLED）、有机场效应晶体管（OFET）以及有机光电晶体管（OPT）。以BTBF-DPh作为发光层的OLED器件展现出蓝色发射，其国际照明委员会（CIE）色坐标为(0.151, 0.069)，最大电流效率达2.96 cd·A⁻¹，外量子效率为4.23%。与此同时，采用BTBF-DPh薄膜制备的OFET器件展现出0.181 cm²·V⁻¹·s⁻¹的载流子迁移率，与噻吩基同类器件性能相当。此外，基于BTBF-DPh的OPT器件的最大响应度与探测率分别可达2.07×10³ A·W⁻¹与5.6×10¹⁵ 琼斯。一方面，本研究合理设计的BTBF-DPh材料具有致密紧密的堆积结构与扩展的π共轭体系，可促进相邻分子间的电荷传输。另一方面，明确的J-聚集效应削弱了BTBF-DPh分子间的偶极-偶极相互作用，而通过替换硫原子所降低的自旋轨道耦合则显著抑制了激子猝灭，从而提升了光致发光性能。上述结果证实，本研究新开发的BTBF-DPh是一种极具应用潜力的多功能有机半导体材料，可用于各类光电器件。