基于溶液加工宽带隙半导体的有机场效应晶体管存储器的研究

发布时间：2018-03-28 18:36

本文选题：有机场效应晶体管存储器　切入点：宽带隙　出处：《南京邮电大学》2017年硕士论文

【摘要】：非易失性有机场效应晶体管(OFET)存储器具有制备工艺简单、成本低、设计性强、非破坏性读取、可与柔性衬底集成、单个器件可以实现多阶存储等优点而备受广泛的关注。但是目前OFET存储器的性能(存储密度、存储稳定性)仍然劣于商业存储器的性能,这限制它们的实际应用。电荷存储层是OFET存储器中控制存储性能的关键元件,其直接影响OFET存储器中电荷俘获和释放过程。因此,设计和制造高效电荷存储层对实现高性能OFET存储器具有重要意义。近年来,小分子材料具有易于提纯、性能稳定、分子和电子结构定义明确、能根据需求进行电子结构和能带的设计等优势引起广泛的关注。但是目前多数研究是基于有机小分子半导体和金属纳米粒子,其存储密度低且电荷泄露严重。而小分子宽带隙半导体,由于它们在LUMO和HOMO之间的宽带隙,俘获电荷可以得到良好的保持。因此,小分子宽带隙半导体是OFET存储器电荷存储层潜在的新的候选物。本论文第一部分通过傅克反应制备了不同孔径的小分子宽带隙半导体风车格子,并探究了它们的电荷捕获能力,该器件成功实现了较稳定的双极性存储特性。其存储窗口达到55 V(负向35 V,正向20 V),维持时间在104 s以上,开关比分别维持在102和103,且具有较稳定的读写擦耐受性。有机风车格子的孔状结构,提供了较多的电荷捕获位点,能够有效地捕获和存储电荷,因此实现了高密度和高稳定性的存储。第二部分通过简单的旋涂工艺制备了高度有序和均匀分布的纳米柱阵列,并研究了纳米柱阵列对器件存储性能的影响。该器件实现了高密度、高速度的存储特性。其存储窗口达到44.8 V,维持时间在104 s以上,开关比维持在105,且具有较稳定的读写擦耐受性。此外,我们通过Matlab仿真的方法,定量的研究了存储窗口和接触面积之间的关系,发现存储窗口强烈依赖于接触面积。因此我们研究提供了一个新的策略实现高性能的非易失OFET存储器。第三部分我们详细研究了基于Pentacene/P13作为活性层的有机异质结场效应晶体管存储器,采用Si/SiO2/WG3/P13/Pentacene/Cu的器件结构。在黑暗中,该器件实现了双极性存储。其存储窗口(约55.33 V),较高的读写擦耐受性(200个读写擦循环后,源漏电流几乎没有衰减)。此外,我们研究了厚度效应对OFET存储器存储性能的影响,随着P13厚度的减小,其存储窗口也随着减小,存储稳定性能增加(双极性存储器件的电子存储时间和空穴存储时间能够维持在5000秒以上,开关比维持在102以上)。因此我们研究提供了一个新的策略实现高性能的非易失异质结OFET存储器。
[Abstract]:Non-volatile FET memory has the advantages of simple fabrication process, low cost, strong design, non-destructive reading, and can be integrated with flexible substrate. However, the performance of OFET memory (storage density, storage stability) is still inferior to that of commercial memory. This limits their practical application. Charge storage layer is the key component in OFET memory to control storage performance, which directly affects the process of charge capture and release in OFET memory. The design and manufacture of high efficiency charge storage layer is of great significance to the realization of high performance OFET memory. In recent years, small molecular materials have been characterized by easy purification, stable performance, clear molecular and electronic structure definitions. The advantages of being able to design electronic structures and energy bands according to demand have attracted wide attention. However, most of the current research is based on organic small molecular semiconductors and metal nanoparticles. Because of their wide band gap between LUMO and HOMO, the capture charge can be kept well. Small molecular wide band gap semiconductor is a potential candidate for charge storage layer of OFET memory. In the first part of this thesis, we have prepared small molecular wide gap semiconductor windmill lattices with different apertures by Fourier reaction, and investigated their charge trapping ability. The device successfully achieves stable bipolar storage characteristics, the memory window reaches 55V (negative 35V, forward 20V), and the maintenance time is more than 104s. The switching ratios are kept at 102 and 103, respectively, and have relatively stable read-write erasability. The pore structure of the organic windmill lattice provides a large number of charge capture sites, which can effectively capture and store charges. Therefore, high density and high stability storage is realized. In the second part, a highly ordered and uniformly distributed nano-column array is fabricated by a simple spin-coating process. The effect of nanoscale array on the storage performance of the device is studied. The device achieves high density and high speed storage characteristics. The storage window is 44.8 V and the maintenance time is more than 104 s. The switching ratio is maintained at 105, and has stable resistance to read and write erasure. In addition, we quantitatively study the relationship between storage window and contact area by Matlab simulation. It is found that memory windows are strongly dependent on contact area. Therefore, we propose a new strategy to implement high-performance non-volatile OFET memory. In the third part, we study the organic heterostructure based on Pentacene/P13 as the active layer in detail. Field effect transistor memory, Si/SiO2/WG3/P13/Pentacene/Cu device structure. In the dark, the device realizes bipolar storage. Its memory window (about 55.33 V / L) has high read-write erasure tolerance (200 read-write erasure cycles, source and drain current almost no attenuation, in addition, We study the effect of thickness effect on the storage performance of OFET memory. With the decrease of P13 thickness, the storage window decreases, too. Improved storage stability (the electronic storage time and hole storage time of bipolar memory devices can be maintained at more than 5,000 seconds, The switching ratio is kept above 102.Therefore, we propose a new strategy to implement the high performance non-volatile heterojunction OFET memory.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN386;TP333

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