两性离子界面修饰的高增益有机光探测器研究

发布时间：2018-04-27 03:23

  本文选题：两性离子 + 有机光探测器　； 参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：有机光探测器具有质量轻,可以采用溶剂成膜,大面积低成本、柔性基底上制备的优点,而且共轭聚合物材料还可以通过添加或减少支链控制其溶解性和带隙宽度调节光电特性,被广泛的应用在国防、通信、环境监测、遥感控制、化学/生物传感和航空航天等领域。然而,传统高增益有机光探测器是人为的在聚合物表面设计纳米颗粒陷阱诱导电荷的二次注入,很难同时的增加响应度和响应速度。而有机材料的制备过程中必不可少的会引入缺陷,这些缺陷也会捕获电子,只是有机材料的内部陷阱较少,不足以在外部电场的作用下产生高增益。本文以此为出发点,将有机聚合物材料内部的陷阱与有机-无机异质结相结合制备了高增益光探测器。界面修饰材料可以有效的改变电极和活性层之间的界面接触使器件性能显著提高,本文采用两性离子材料wc-1和wc-2对以PCE-10共混PC71BM的光探测器进行了界面修饰,活性层旋涂厚度约为200 nm,热处理方式是旋涂活性层后静置12 h后110℃加热20 min。wc-2以浓度0.75 mg/m L,wc-1以1.5 mg/m L浓度旋涂在ITO上进行界面修饰后器件的外量子效率增加12%以上、暗电流下降一个数量级、器件的探测率达到1013 Jones、瞬态响应时间达到微妙级、线性动态范围(LDR)超过85 d B。因PCE-10材料内部陷阱含量太低,器件在外部偏压作用下增益并不明显。据此,使用赖氨酸修饰含有较多陷阱的PBDTT-DPP共混PC71BM材料制备了在室温0.8 V偏压下外量子效率3500%、比探测率值高于无机Si探测器达到了1014 Jone、响应时间快、线性度大的高增益光探测器器件。高增益有机光探测器件的工作原理是Mo O3/Al复合层和活性层给体材料PBDTT-DPP材料接触后,电子被存在于其中的陷阱所捕获,在两相交界处形成了空间电荷限制区(SCR),在器件内部形成了N-P-N杂化异质结结构,分别是PCBM/PBDTT-DPP的有机本体异质结(N-P)和PBDTT-DPP/Mo O3的有机-无机异质结(P-N),利用器件内部光生载流子产生的微小电流作为开关诱导外部电流注入使器件在正偏压下具有高增益现象。根据这个原理,如果人为的控制聚合物材料中的陷阱密度并将其应用到探测领域,高增益光探测器件必将获得突破性的发展。
[Abstract]:Organic photodetectors have the advantages of light weight, solvent film formation, large area, low cost and flexible substrate. Moreover, conjugated polymer materials can control their solubility and bandgap width by adding or reducing the branching chain, which can be widely used in defense, communication, environmental monitoring, remote sensing control. Chemical / biological sensing and aerospace. However, the conventional high gain organic photodetectors are artificially designed on the polymer surface to create nanoparticles trap induced charge secondary injection, it is difficult to simultaneously increase the responsivity and response speed. However, defects will be introduced in the preparation of organic materials, and these defects will trap electrons. However, the internal traps of organic materials are less, which is not enough to produce high gain under the action of external electric field. In this paper, a high gain photodetector was prepared by combining the trap of organic polymer material with the organic inorganic heterojunction. The interfacial modification material can effectively change the interface contact between the electrode and the active layer to improve the performance of the device. In this paper, wc-1 and wc-2 are used to modify the interface of the photodetector with PCE-10 blend PC71BM. The active layer spin-coating thickness is about 200nm.The heat treatment method is that the active layer is spin-coated for 12 h, then heated at 110 鈩，

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