石墨烯量子点的制备及其在有机电子器件中的应用研究

发布时间：2018-05-21 05:05

本文选题：石墨烯量子点 + 三体系活性层结构　；参考：《福州大学》2014年硕士论文

【摘要】：石墨烯量子点(Graphene Quantum Dots, GQDs)与半导体量子点相比,具有良好的化学稳定性、低细胞毒性以及独特的荧光特性。凭借这些突出优势,GQDs已在生物成像、电化学传感、催化技术等领域展现出诱人的应用前景,其研究具备环境友好、节约资源、便携等备受关注的研究意义和价值。目前制备GQDs的方法仍存在荧光不可控、粒径较难一致、稳定性差等问题；它在有机电子器件中的应用具有优越前景,但这方面研究却仍处于初始阶段。选择合适的碳源制备荧光稳定、高产率的GQDs,并将其用于制备高性能有机太阳能电池、有机存储等器件的研究成为本课题的出发点。主要工作和结论如下：一、本文成功制备了溶于氯苯溶液具有蓝色荧光发射的GQDs。采用化学溶液法,在磁力搅拌加热条件下裁剪双壁碳纳米管,获得10nm-100nm范围的石墨烯纳米片,经过分离提取处理获得理想的GQDs,其主要表征结果如下：尺寸小于10nm,具有明显的晶格条纹,厚度在2-3nm,具有强烈的蓝色荧光发射谱、优良的激发波长依赖性以及尺寸相关的荧光寿命特性。二、制备基于GQDs三体系活性层结构的有机太阳能电池,获得较高能量转换效率的器件。在P3HT:PCBM体系有机太阳能电池中引入GQDs,器件的吸收光谱得到提高并表现出微量红移,能量转换效率达到4.35%；优化器件性能发现PCBM比例为0.6时,器件能量转换效率达到5.24%；在新型体系PTB7:PC7iBM中引入GQDs,获得器件的能量转换效率达6.6%,并发现提高GQDs浓度可增强器件的电流密度。三、引入GQDs制备性能优异的柔性存储器件,在大容量多值存储领域具有一定的应用价值。制备基于PMMA:GQDs功能层的柔性存储器件,开口率可达103,多次弯曲后器件性能基本不变；基于PVK:GQDs功能层制备的器件具有低驱动低功耗且稳定的双稳性能；设计并制备PI/GQDs/PI叠层结构的器件经近千次的扫描仍具有良好的阻变性,这对多层存储单元的实现具有一定研究意义。总之,本论文结合理论和实践,运用科学的实验方法研究制备了性能稳定、粒径均一、具有优良荧光特性的石墨烯量子点材料并将其巧妙地应用于有机太阳能电池以及有机存储领域,获得性能优良稳定的电子器件。由此可见,本课题的研究具有一定程度的创新意义和应用价值。
[Abstract]:Compared with semiconductor quantum dots, graphene Quantum Dots, GQDs) has good chemical stability, low cytotoxicity and unique fluorescence properties. With these outstanding advantages, GQDs have shown attractive application prospects in the fields of biological imaging, electrochemical sensing, catalytic technology and so on. The research of GQDs has attracted much attention because of its environmental friendliness, resource saving and portability. At present, there are still some problems in the preparation of GQDs, such as uncontrollable fluorescence, difficult uniformity of particle size and poor stability, etc. Its application in organic electronic devices is promising, but the research in this field is still in the initial stage. Choosing suitable carbon source to prepare GQDs with stable fluorescence and high yield is the starting point of the research on the preparation of high performance organic solar cells and organic storage devices. The main work and conclusions are as follows: firstly, GQDssoluble in chlorobenzene solution with blue fluorescence emission have been successfully prepared. Using the chemical solution method, the double-walled carbon nanotubes were cut under the condition of magnetic stirring and heating, and the graphene nanoplates in the 10nm-100nm range were obtained. The ideal GQDs were obtained by separation and extraction. The main characterization results are as follows: the size is less than 10 nm, the lattice stripes are obvious, the thickness is 2 ~ 3 nm, and the blue fluorescence emission spectrum is strong. Excellent excitation wavelength dependence and size dependent fluorescence lifetime. Secondly, organic solar cells based on GQDs three-system active layer structure are fabricated to obtain high energy conversion efficiency devices. When GQDs were introduced into the organic solar cells of P3HT:PCBM system, the absorption spectra of the devices were improved, and the energy conversion efficiency reached 4.35%, and when the PCBM ratio was 0.6, the energy conversion efficiency was 4.35%. The energy conversion efficiency of the device is up to 5.24.The energy conversion efficiency of the device is up to 6.6 by introducing GQDs into the new system PTB7:PC7iBM, and it is found that increasing the GQDs concentration can enhance the current density of the device. Thirdly, flexible memory devices with excellent performance are fabricated by GQDs, which has certain application value in the field of large capacity multi-valued memory. A flexible memory device based on PMMA:GQDs functional layer is fabricated with an opening rate of 103, and the device performance is basically unchanged after multiple bending. The device based on PVK:GQDs functional layer has low drive and low power consumption and stable bistability. The design and fabrication of PI/GQDs/PI laminated devices still have good resistive properties after nearly 1,000 scans, which has a certain significance for the realization of multilayer memory cells. In a word, this paper combines theory and practice, using scientific experimental method to study and prepare stable performance and uniform particle size. Graphene quantum dots (QDs) with excellent fluorescence properties have been used in organic solar cells and organic storage to obtain excellent and stable electronic devices. Thus, the research of this subject has some innovative significance and application value.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ127.11;TM914.4

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