【摘要】：石墨烯是一種零帶隙半導體材料,具有超寬光譜吸收、超高的載流子遷移率等性能,使其在超快光電探測領域有很好的應用前景。然而,作為光電探測器的光敏材料,石墨烯有兩個本征的不足,一是對光的吸收少,僅為2.3%,進而石墨烯基光電探測器的外量子效率很低;二是石墨烯光生激子壽命超短,即光生電子-空穴對產(chǎn)生后迅速復合,造成無法有效抽取進而形成光電流。因此,對石墨烯光電探測器的功能化是十分必要的,即在現(xiàn)有的基礎上,對器件的光吸收率或激子壽命進行提升,進而提升石墨烯基探測器的光探測性能。本文采用硫化鉛量子點層層旋涂法功能化石墨烯探測器,并制備成高響應度、寬光譜的光電探測器。首先研究了石墨烯的轉移和機械剝離技術,將化學氣相沉積法生長的銅基石墨烯轉移至硅襯底并成功機械剝離出單層石墨烯。然后將轉移的石墨烯和機械剝離石墨烯經(jīng)過光刻、刻蝕等半導體工藝制備成場效應晶體管結構光電探測器,其中石墨烯為溝道材料。通過調(diào)變量子點外包覆的配體種類和旋涂層數(shù),對器件進行功能化并測試器件光電性能,研究了配體和量子點的電荷轉移機制。最后探索了石墨烯在成像領域的應用,制備了像元為128×1的線陣感光器件,使器件的像元間距和尺寸均符合目前實際的封裝和流片測試要求,每個像元均為石墨烯-量子點復合光電探測器,并通過光電測試表征線陣器件的均勻性和穩(wěn)定性較好。本文采用的量子點功能化石墨烯的方法操作簡單,條件溫和,在室溫和大氣中即可進行,并且可以大規(guī)模制備。采用該方法制備的光電探測器具有響應度較高、光譜響應范圍寬、響應速度快等優(yōu)點,證實功能化石墨烯光電探測器在光電成像領域有很大的應用潛力。
[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.
【學位授予單位】：華北電力大學(北京)
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN36

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相關期刊論文 前1條

1 魏芹芹;何建廷;;氧等離子體刻蝕對石墨烯性能的影響[J];功能材料;2014年24期

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本文編號：2328782