石墨烯光电探测器的功能化研究
发布时间：2018-11-13 10:08
【摘要】：石墨烯是一种零带隙半导体材料,具有超宽光谱吸收、超高的载流子迁移率等性能,使其在超快光电探测领域有很好的应用前景。然而,作为光电探测器的光敏材料,石墨烯有两个本征的不足,一是对光的吸收少,仅为2.3%,进而石墨烯基光电探测器的外量子效率很低;二是石墨烯光生激子寿命超短,即光生电子-空穴对产生后迅速复合,造成无法有效抽取进而形成光电流。因此,对石墨烯光电探测器的功能化是十分必要的,即在现有的基础上,对器件的光吸收率或激子寿命进行提升,进而提升石墨烯基探测器的光探测性能。本文采用硫化铅量子点层层旋涂法功能化石墨烯探测器,并制备成高响应度、宽光谱的光电探测器。首先研究了石墨烯的转移和机械剥离技术,将化学气相沉积法生长的铜基石墨烯转移至硅衬底并成功机械剥离出单层石墨烯。然后将转移的石墨烯和机械剥离石墨烯经过光刻、刻蚀等半导体工艺制备成场效应晶体管结构光电探测器,其中石墨烯为沟道材料。通过调变量子点外包覆的配体种类和旋涂层数,对器件进行功能化并测试器件光电性能,研究了配体和量子点的电荷转移机制。最后探索了石墨烯在成像领域的应用,制备了像元为128×1的线阵感光器件,使器件的像元间距和尺寸均符合目前实际的封装和流片测试要求,每个像元均为石墨烯-量子点复合光电探测器,并通过光电测试表征线阵器件的均匀性和稳定性较好。本文采用的量子点功能化石墨烯的方法操作简单,条件温和,在室温和大气中即可进行,并且可以大规模制备。采用该方法制备的光电探测器具有响应度较高、光谱响应范围宽、响应速度快等优点,证实功能化石墨烯光电探测器在光电成像领域有很大的应用潜力。
[Abstract]:Graphene is a kind of zero-band gap semiconductor material, which has the properties of ultra-wide spectrum absorption and ultra-high carrier mobility, so it has a good application prospect in the field of ultra-fast photoelectric detection. However, as a kind of Guang Min material, graphene has two inherent defects. One is that the absorption of light is less than 2.3, and the external quantum efficiency of graphene based photodetector is very low. The second is that the lifetime of graphene induced excitons is very short, that is, the photogenerated electron-hole pair is rapidly recombined after the generation, which makes it impossible to extract effectively and form photocurrent. Therefore, it is necessary to functionalize graphene photodetectors, that is, to improve the photoabsorptivity or exciton lifetime of the devices on the basis of the existing ones, and then to improve the photodetection performance of graphene based detectors. In this paper, high responsivity and wide spectrum photodetectors have been prepared by using the lead sulfide quantum dots layer by layer spin-coating method to functionalize graphene detectors. Firstly, the transfer and mechanical stripping techniques of graphene were studied. The copper-based graphene grown by chemical vapor deposition was transferred to silicon substrate and the monolayer graphene was successfully stripped. Then the transferred graphene and mechanically stripped graphene were prepared by photolithography etching and other semiconductor processes to form a field effect transistor structure photodetector in which graphene is a channel material. The charge transfer mechanism of the ligand and quantum dots was studied by using the ligand type and the number of spin coatings coated on the subpoints of the variable tuning variables to functionalize the devices and test the photoelectric properties of the devices. Finally, the application of graphene in imaging field is explored, and a linear array photosensitive device with 128 脳 1 pixel is fabricated. The pixel spacing and size of the device meet the requirements of packaging and flow sheet testing. Each pixel is graphene-quantum dot composite photodetector and the uniformity and stability of linear array devices are characterized by photoelectric measurement. The QDs functionalized graphene method in this paper is simple in operation, mild in conditions, can be carried out at room temperature and atmosphere, and can be prepared on a large scale. The photodetectors prepared by this method have the advantages of high responsivity, wide spectral response range and fast response speed. It is proved that the functional graphene photodetectors have great application potential in the field of photoelectric imaging.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN36
本文编号：2328782
[Abstract]:Graphene is a kind of zero-band gap semiconductor material, which has the properties of ultra-wide spectrum absorption and ultra-high carrier mobility, so it has a good application prospect in the field of ultra-fast photoelectric detection. However, as a kind of Guang Min material, graphene has two inherent defects. One is that the absorption of light is less than 2.3, and the external quantum efficiency of graphene based photodetector is very low. The second is that the lifetime of graphene induced excitons is very short, that is, the photogenerated electron-hole pair is rapidly recombined after the generation, which makes it impossible to extract effectively and form photocurrent. Therefore, it is necessary to functionalize graphene photodetectors, that is, to improve the photoabsorptivity or exciton lifetime of the devices on the basis of the existing ones, and then to improve the photodetection performance of graphene based detectors. In this paper, high responsivity and wide spectrum photodetectors have been prepared by using the lead sulfide quantum dots layer by layer spin-coating method to functionalize graphene detectors. Firstly, the transfer and mechanical stripping techniques of graphene were studied. The copper-based graphene grown by chemical vapor deposition was transferred to silicon substrate and the monolayer graphene was successfully stripped. Then the transferred graphene and mechanically stripped graphene were prepared by photolithography etching and other semiconductor processes to form a field effect transistor structure photodetector in which graphene is a channel material. The charge transfer mechanism of the ligand and quantum dots was studied by using the ligand type and the number of spin coatings coated on the subpoints of the variable tuning variables to functionalize the devices and test the photoelectric properties of the devices. Finally, the application of graphene in imaging field is explored, and a linear array photosensitive device with 128 脳 1 pixel is fabricated. The pixel spacing and size of the device meet the requirements of packaging and flow sheet testing. Each pixel is graphene-quantum dot composite photodetector and the uniformity and stability of linear array devices are characterized by photoelectric measurement. The QDs functionalized graphene method in this paper is simple in operation, mild in conditions, can be carried out at room temperature and atmosphere, and can be prepared on a large scale. The photodetectors prepared by this method have the advantages of high responsivity, wide spectral response range and fast response speed. It is proved that the functional graphene photodetectors have great application potential in the field of photoelectric imaging.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN36
【参考文献】
相关期刊论文 前1条
1 魏芹芹;何建廷;;氧等离子体刻蚀对石墨烯性能的影响[J];功能材料;2014年24期
，本文编号：2328782
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