Optimization of Solubility, Film Morphology and Photodetector Performance by Molecular Side-Chain Engineering of Low-Bandgap Thienothiadiazole-Based Polymers
Optimization of Solubility, Film Morphology and Photodetector Performance by Molecular Side-Chain Engineering of Low-Bandgap Thienothiadiazole-Based Polymers
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通过低带隙噻吩并噻二唑基聚合物的分子侧链工程优化溶解度、薄膜形态和光电探测器性能
DOI：
10.1002/adfm.201401948
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发表时间：
2014
影响因子：
19
通讯作者：
Wang Zhi Yuan
中科院分区：
文献类型：
--
作者：
Qi Ji;Zhou Xiaokang;Yang Dezhi;Qiao Wenqiang;Ma Dongge;Wang Zhi Yuan
为了研究侧链结构对聚合物性能的影响，优化聚合物光电探测器的性能，设计并合成了一系列主链上含有三硫杂环并[3，4-b]噻二唑单元但具有不同数目相同侧链的D-A型低禁带聚合物。侧链含量的变化会影响聚合物的溶解性、分子堆积和薄膜形态，进而影响光电探测器的性能，特别是在光响应性和暗电流方面。X射线衍射图表明，侧链越多，分子有序性越强。原子力显微镜研究表明，聚合物光电探测器中的有源层必须具有合适的形貌才能获得较高的光电流和较低的暗电流。使用BCP作为空穴阻挡层(10 Nm)，基于P4的光电探测器在800 nm处表现出了1.4×1012琼斯的最佳性能，这是报道的最好的聚合物光电探测器之一，甚至可以与硅光探测器相媲美。
A series of donor–acceptor (D‐A) type low‐bandgap polymers containing the terthiophene and thieno[3,4‐b]thiadiazole units in the main chain but different numbers of identical side chains are designed and synthesized in order to study the effect of side chain on the polymer properties and optimize the performance of polymer photodetectors. Variation in the side chain content can influence the polymer solubility, molecular packing, and film morphology, which in turn affects the photodetector performance, particularly with regard to the photoresponsivity and dark current. X‐ray diffraction patterns indicate that molecular ordering increases with more side chains. Atomic force microscopy shows that appropriate morphology of the active layer in the polymer photodetector is necessary for high photocurrent and low dark current. Using BCP as a hole blocking layer (10 nm), the photodetector based onP4exhibits the optimized performance with specific detectivity of 1.4 × 1012Jones at 800 nm, which is among the best reported values for polymer photodetectors and even comparable to that of a silicon photodetector.