【摘要】：光電探測器被廣泛的應(yīng)用在我們的日常生產(chǎn)生活中。目前在可見光波段,光電探測器所用的最主要的材料還是硅,但為了實現(xiàn)特定功能,如拓展、改變探測范圍,需要硅與其他材料結(jié)合。但值得注意的是,三維材料之間因為存在晶格失配的問題,很難大面積集成。近年來,二維材料持續(xù)吸引著人們的目光,特別是石墨烯和過渡金屬硫化物(TMDCs)。二維材料有著一些共同的特性:分子在層內(nèi)由共價鍵連接,層間由范德華力結(jié)合。另外,二維材料沒有表面懸掛鍵的特性,使得分離此種材料變得簡單,同時很容易與其他材料進(jìn)行復(fù)合制作異質(zhì)結(jié)結(jié)構(gòu)。特別值得注意的是TMDCs擁有較為理想的禁帶寬度(1.06-2.88 eV),這就使其可以作為光的吸收層用到可見光探測領(lǐng)域,特別是用于高響應(yīng)度、低功耗、柔性器件中。眾所周知,光電二極管是光電探測器的基本結(jié)構(gòu)之一,利用TMDCs材料制作二極管結(jié)構(gòu)的研究可以分成兩種:TMDCs-TMDCs(2D-2D)、TMDCs-傳統(tǒng)材料(2D-3D)。這里我們重點研究石墨烯/硅、過渡金屬硫化物/硅兩種異質(zhì)結(jié)結(jié)構(gòu)的制作及性能。首先本文利用二維材料生長和濕法刻蝕的方式制作了Si/Graphene肖特基結(jié),并研究了此肖特基結(jié)的光電特性,以及在不同溫度下的二極管性能,發(fā)現(xiàn)其光響應(yīng)度達(dá)0.5 A/W,響應(yīng)時間為164μs,具有較好的光電特性。在對其進(jìn)行溫度測試時,我們發(fā)現(xiàn)器件在低溫下存在反向擊穿現(xiàn)象,通過后期實驗的對比也對此作出了解釋。其次文章通過改進(jìn)制作工藝,棄除濕法刻蝕的步驟,利用半導(dǎo)體工藝兼容的方式制作了n-Si/WS_2同型異質(zhì)結(jié)結(jié)構(gòu),并對其光電特性、溫度特性以及光電流產(chǎn)生位置問題做了系統(tǒng)的研究。器件同樣具有較好的光電特性:光響應(yīng)度達(dá)1.2 A/W,最短響應(yīng)時間為8μs。且由于改進(jìn)制作工藝的原因,器件在低溫環(huán)境中不再出現(xiàn)反向擊穿電流。在對光電流產(chǎn)生位置的研究中,通過光電流mapping的測量,我們發(fā)現(xiàn)如果外加電壓較大,在非異質(zhì)結(jié)區(qū)仍然會有較大的光電流產(chǎn)生,本文對此現(xiàn)象也做出了解釋。另外本文還研究了量子點修飾對器件光響應(yīng)的影響,發(fā)現(xiàn)通過旋涂碳量子點可以在各個波段提高器件的響應(yīng)度。最后通過制作更為常見的p-Si/WS_2異質(zhì)結(jié)結(jié)構(gòu)對器件擊穿特性做了重點研究。并發(fā)現(xiàn)在齊納擊穿點附近器件光響應(yīng)達(dá)到5.6 A/W。本文為研究硅基二維材料集成器件奠定了一定的基礎(chǔ)。
[Abstract]:Photodetector is widely used in our daily production and life. At present, the most important material used in photodetectors is silicon, but in order to achieve specific functions, such as expanding and changing the detection range, silicon needs to be combined with other materials. However, it is worth noting that it is difficult to integrate large areas between three-dimensional materials because of the problem of lattice mismatch. In recent years, two-dimensional materials have attracted people's attention, especially graphene and transition metal sulfides (TMDCs). Two-dimensional materials have some common properties: molecules are connected by covalent bonds in the layer, and the layers are combined by van der Waals force. In addition, two-dimensional materials do not have the characteristics of surface suspension bonds, which makes the separation of such materials simple, and it is easy to composite with other materials to fabricate heterojunction structures. It is especially worth noting that TMDCs has an ideal band gap (1.06 eV), 2.88 eV), which makes it suitable for visible light detection as an absorption layer of light, especially in high responsivity, low power consumption and flexible devices. It is well known that photodiodes are one of the basic structures of photodetectors. The fabrication of diode structures using TMDCs materials can be divided into two types: TMDCs-TMDCs (2D-2D) and TMDCs- traditional materials (2D-3D). In this paper, we focus on the fabrication and properties of graphene / silicon and transition metal sulfides / silicon. Firstly, the Si/Graphene Schottky junction was fabricated by two-dimensional material growth and wet etching. The photoelectrical properties of the Schottky junction and the diode properties at different temperatures were studied. It was found that the photoresponse of the Schottky junction was up to 0.5A / W, The response time is 16.4 渭 s, which has good photoelectric characteristics. During the temperature test, we find that the device has reverse breakdown phenomenon at low temperature, which is explained by the comparison of the later experiments. Secondly, by improving the fabrication process and abandoning the step of dehumidification etching, the n-Si/WS_2 heterojunction structure is fabricated by semiconductor process compatibility, and the photoelectric characteristics of the heterojunction are investigated. The temperature characteristics and the position of photocurrent are studied systematically. The device also has good photoelectric properties: the optical response is 1.2 A 鈮，

本文編號：2475355