一种异靛蓝衍生半导体的合成、表征和OTFT应用

Preparation and Characterization of an Isoindigo-Derived Semiconductor and Its OTFT Application

以4-癸基十六烷基溴和6-溴二氢吲哚-2,3-二酮为原料,将4-癸基十六烷基侧链引入到(3E,7E)-3,7-双(2-氧代二氢吲哚-3-亚基)苯并[1,2-b:4,5-b']二呋喃-2,6(3H,7H)-二酮(IBDF)中合成了IBDF-26,再与(E)-1,2-双(三丁基甲锡烷基)乙烯通过Stille偶合制备了基于异靛蓝衍生大稠环聚合物的半导体PIBDFV-26。采用TGA、DSC、UV、CV、XRD、AFM对PIBDFV-26的性能、结构、形貌进行了表征。结果表明,基于异靛蓝大稠环的半导体PIBDFV-26在三氯乙烯(TCE)中的溶解性良好,具有良好的热稳定性,HOMO/LUMO能级为–5.96eV/–4.62eV,光学帯隙为1.34eV。XRD结果表明,聚合物链沿边沿取向形成层状晶体结构,层间距为2.55×10^(–6) mm,π–π堆积距离为3.46×10^(–7) mm。AFM显示,退火处理的PIBDFV-26薄膜表面含有纳米级的晶状颗粒。对PIBDFV-26组装的有机薄膜晶体管(OTFT)器件进行了测试,结果显示OTFT器件表现出电子传输(negative,n)型沟道的电荷传输特性。150℃退火处理的聚合物薄膜的平均电子迁移率为0.13 cm^2/(V?s)。

6-Bromo-1-(4-decyl-hexadecyl)-1 H-indole-2,3-dione was prepared from 4-decyl-1-hexadecyl bromide with 6-bromoindoline-2,3-dione.Compound IBDF-26 was obtained by introducing 4-decyl-1-hexadecyl side chain into(3 E,7 E)-3,7-bis(2-oxoindolin-3-ylidene)benzo [1,2-b: 4,5-b’]difuran-2,6(3 H,7 H)-dione(IBDF).Then a palladium-catalyzed Stille coupling reaction of intermediate IBDF-26 with(E)-1,2-bis(tributylstannyl) etheneled to polymer semiconductor PIBDFV-26 based on isoindigo. The properties,structure and morphology of PIBDFV-26 were characterized by TGA, DSC, UV, CV, XRD and AFM. The results show that semiconductor PIBDFV-26 has good solubility in trichloroethylene(TCE), and processes excellent thermal stability. The HOMO/LUMO energy level is –5.96 eV/–4.62 eV and the optical bandgap is 1.34 eV. XRD results reveal that the polymer chains are likely packed in a lamellar crystalline structure with an edge-on orientation and the d-spacing and π–π stacking distance are 2.55×10^–6 mm and 3.46 ×10^–7 mm, respectively. AFM shows that the surface of the annealed PIBDFV-26 film contains nano-crystalline particles. PIBDFV-26 was assembled into an organic thin film transistor(OTFT) device and tested. The results demonstrate that the OTFT device exhibits n-type charge transfer characteristic.The average electron mobility for a 150 ℃-annealed PIBDFV-26 film is 0.13 cm^2/(V·s).