High Charge Carrier Mobility, Low Band Gap Donor-Acceptor Benzothiadiazole-oligothiophene Based Polymeric Semiconductors
High Charge Carrier Mobility, Low Band Gap Donor-Acceptor Benzothiadiazole-oligothiophene Based Polymeric Semiconductors
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DOI：
10.1021/cm3021929
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发表时间：
2012-11-13
影响因子：
8.6
通讯作者：
Reichmanis, Elsa
中科院分区：
文献类型：
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作者：
Fu, Boyi;Baltazar, Jose;Reichmanis, Elsa
合成并表征了一系列苯并噻二唑低聚噻吩和低聚噻吩亚乙烯基给体-受体共聚物。这些低光学带隙材料（类似于1.5 eV）能够吸收400-800 nm范围内的光子，并表现出良好的热稳定性。它们的空穴迁移率，确定使用的有机场效应晶体管（OFET）的架构，在3个数量级的范围内变化，并强烈相关的分子排序和各自的薄膜的形态。聚（苯并噻二唑-六噻吩）PBT 6的旋涂膜在OFET衬底上表现出高度结晶的层状π-π堆叠的边缘取向，具有约为100 nm的空穴迁移率。0.2厘米（2）/Vs含亚乙烯基的类似物PBT 6V 2和PBT 6V 2 '是无定形的，并且表现出非常低的迁移率。PBT 6的分子量对电子性质有很大的影响：具有较低分子量的样品表现出比高分子量同系物低约1个数量级的迁移率，并且吸收最大值明显蓝移。PBT 6的空穴迁移率进一步提高了约1倍。3通过滴铸制造OFET。用该方法制备的OFPs的迁移率高达0.75 cm（2）/V.s，I-ON/OFF比在10（6）-10（7）范围内。这些结果表明，潜在的苯并噻二唑单元纳入聚噻吩衍生物开发，高迁移率的半导体聚合物。
A series of benzothiadiazole oligothiophene and oligo(thienylene vinylene) donor-acceptor (D-A) copolymers were synthesized and characterized. These low optical band gap materials (similar to 1.5 eV) are capable of absorbing photons in the range of 400-800 nm and exhibit good thermal stability. Their hole mobilities, determined using an organic field-effect transistor (OFET) architecture, vary over a range of 3 orders of magnitude and strongly correlate with the molecular ordering and morphology of the respective thin films. Spin-coated films of the poly(benzothiadiazole-sexithiophene) PBT6, which exhibits a highly crystalline lamellar pi-pi stacked edge-on orientation on the OFET substrate, possesses a hole mobility of ca. 0.2 cm(2)/V.s. Vinylene-containing analogs PBT6V2 and PBT6V2' are amorphous and exhibit very low mobilities. The molecular weight of PBT6 has a strong influence on the electronic properties: a sample with a lower molecular weight exhibits a mobility approximately 1 order of magnitude lower than the high molecular weight homologue, and the absorption maximum is appreciably blue-shifted. The hole mobility of PBT6 is further enhanced by a factor of ca. 3 through fabrication of the OFET by drop casting. OFETs fabricated by this process exhibit mobilities of up to 0.75 cm(2)/V.s and I-ON/OFF ratios in the range of 10(6)-10(7). These results demonstrate the potential of incorporating benzothiadiazole units into polythiophene derivatives to develop, high-mobility semiconducting polymers.