發(fā)布時(shí)間：2018-11-13 10:08

【摘要】：石墨烯是一種零帶隙半導(dǎo)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(cè)領(lǐng)域有很好的應(yīng)用前景。然而,作為光電探測(cè)器的光敏材料,石墨烯有兩個(gè)本征的不足,一是對(duì)光的吸收少,僅為2.3%,進(jìn)而石墨烯基光電探測(cè)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(duì)產(chǎn)生后迅速?gòu)?fù)合,造成無(wú)法有效抽取進(jìn)而形成光電流。因此,對(duì)石墨烯光電探測(cè)器的功能化是十分必要的,即在現(xiàn)有的基礎(chǔ)上,對(duì)器件的光吸收率或激子壽命進(jìn)行提升,進(jìn)而提升石墨烯基探測(cè)器的光探測(cè)性能。本文采用硫化鉛量子點(diǎn)層層旋涂法功能化石墨烯探測(cè)器,并制備成高響應(yīng)度、寬光譜的光電探測(cè)器。首先研究了石墨烯的轉(zhuǎn)移和機(jī)械剝離技術(shù),將化學(xué)氣相沉積法生長(zhǎng)的銅基石墨烯轉(zhuǎn)移至硅襯底并成功機(jī)械剝離出單層石墨烯。然后將轉(zhuǎn)移的石墨烯和機(jī)械剝離石墨烯經(jīng)過(guò)光刻、刻蝕等半導(dǎo)體工藝制備成場(chǎng)效應(yīng)晶體管結(jié)構(gòu)光電探測(cè)器,其中石墨烯為溝道材料。通過(guò)調(diào)變量子點(diǎn)外包覆的配體種類和旋涂層數(shù),對(duì)器件進(jìn)行功能化并測(cè)試器件光電性能,研究了配體和量子點(diǎn)的電荷轉(zhuǎn)移機(jī)制。最后探索了石墨烯在成像領(lǐng)域的應(yīng)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(shí)際的封裝和流片測(cè)試要求,每個(gè)像元均為石墨烯-量子點(diǎn)復(fù)合光電探測(cè)器,并通過(guò)光電測(cè)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(diǎn)功能化石墨烯的方法操作簡(jiǎn)單,條件溫和,在室溫和大氣中即可進(jìn)行,并且可以大規(guī)模制備。采用該方法制備的光電探測(cè)器具有響應(yīng)度較高、光譜響應(yīng)范圍寬、響應(yīng)速度快等優(yōu)點(diǎn),證實(shí)功能化石墨烯光電探測(cè)器在光電成像領(lǐng)域有很大的應(yīng)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(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN36

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 魏芹芹;何建廷;;氧等離子體刻蝕對(duì)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(hào)：2328782