【摘要】：相比于傳統(tǒng)的塊體材料,低維納米材料和納米結(jié)構(gòu)表現(xiàn)出獨特的電學(xué)、光學(xué)、磁學(xué)等物理性能,因而具有重要的應(yīng)用價值。近年來的研究表明,以石墨烯為代表的二維層裝材料具有優(yōu)異的物理和化學(xué)性能,在半導(dǎo)體、電子器件、能源儲存與轉(zhuǎn)化方面已初步顯示出良好的社會價值和經(jīng)濟(jì)效益。與此同時,要實現(xiàn)大規(guī)模的工業(yè)級二維材料的規(guī)�；孕枰芏嗟呐�,其中樣品的可控制備是應(yīng)用的基礎(chǔ)。以石墨烯為例,目前多數(shù)的制備工藝是需要高溫條件下進(jìn)行,但是高溫的合成條件大大限制了石墨烯與半導(dǎo)體工業(yè)相結(jié)合,因此開發(fā)低溫條件石墨烯薄膜的合成具有重要意義。此外,層狀六方氮化硼和半導(dǎo)體類的二維材料是對半金屬性石墨烯的有力補充,初步的研究己經(jīng)證實前者對于石墨烯等材料電學(xué)性能的提升有顯著的作用,而后者對于開發(fā)出光電探測器、太陽能電池、顯示等領(lǐng)域?qū)⒂芯薮髴?yīng)用潛力。然而,當(dāng)前這兩類材料的合成的可控性并不好,結(jié)果具有極大的隨機(jī)性,阻礙了二維異質(zhì)結(jié)等納米復(fù)合結(jié)構(gòu)的進(jìn)一步應(yīng)用。針對這些二維材料合成的問題,我們選取半金屬類石墨烯、絕緣體六方氮化硼、拓?fù)浣^緣體和半導(dǎo)體二硫化鎢為研究對象,通過化學(xué)氣相沉積法,對這幾種二維材料進(jìn)行了可控合成、結(jié)構(gòu)表征、物性測量以及初步的應(yīng)用探究,相關(guān)研究結(jié)果有望對于低維納米材料的有效合成和規(guī)模應(yīng)用提供有益的參考。本論文主要取得的研究結(jié)果包括以下三個方面:1.利用化學(xué)氣相沉積法在氟金云母、硅/二氧化硅等基底上合成出具有層狀結(jié)構(gòu)的高質(zhì)量三元拓?fù)浣^緣鉍硒碲單晶納米片(Bi2Se3xTe3(1-x))。通過調(diào)節(jié)硒摻雜的濃度實現(xiàn)了Bi2Se3xTe3(1-x 微觀結(jié)構(gòu)的調(diào)制,利用拉曼光譜對不同硒摻雜的樣品進(jìn)行了探索。研究結(jié)果發(fā)現(xiàn)隨著硒摻雜量的提高,合成出的Bi2Se3xTe3(1-x)納米片的拉曼特征峰的位置會向高頻方向移動,并表現(xiàn)出不連續(xù)變化特征。此研究結(jié)果對于合成高質(zhì)量的拓?fù)浣^緣體及其物性探索具有參考價值。2.利用常壓低溫化學(xué)氣相沉積法合成出超薄的大面積石墨烯薄膜(graphene films).在溫度低至500℃時,通過調(diào)整實驗參數(shù)在銅箔和覆蓋有100nm銅的玻璃基板上均實現(xiàn)了厚度為2-5nm石墨烯膜的生長。研究結(jié)果表明,低溫合成出的石墨烯膜在400-700nm透光性超過90%,并且具有較好的方塊電阻值。此方法為直接在半導(dǎo)體基板上低溫生長超薄膜提供了 一種新途徑。3.利用化學(xué)氣相沉積法在硅/二氧化硅基底上合成出高質(zhì)量的層狀半導(dǎo)體硫化鎢單晶(WS2)。通過微納加工工藝,將合成的WS2制備成器件并測試了其傳感性能。研究結(jié)果發(fā)現(xiàn),WS2器件具有良好的水蒸氣響應(yīng)行為,隨著測試環(huán)境中水蒸氣的含量的增加器件電流明顯提高,從而實現(xiàn)了基于WS2的氣體濕度傳感器。此研究對于二維層狀半導(dǎo)體類材料的器件應(yīng)用具有借鑒意義。
[Abstract]:Compared with traditional bulk materials, low-dimensional nanomaterials and nanostructures exhibit unique physical properties, such as electrical, optical and magnetic properties, so they have important application value. Recent studies have shown that graphene as the representative of two-dimensional laminated materials have excellent physical and chemical properties, in semiconductor, electronic devices, energy storage and conversion has shown a good social value and economic benefits. At the same time, a lot of efforts are needed to realize the large-scale of industrial two-dimensional materials, in which the controlled preparation of samples is the basis of application. Taking graphene as an example, most of the current preparation processes need to be carried out at high temperature, but the synthesis conditions at high temperature greatly limit the combination of graphene and semiconductor industry, so it is of great significance to develop graphene thin films at low temperature. In addition, layered hexagonal boron nitride and semiconductor two-dimensional materials are complementary to semi-metallic graphene. Preliminary studies have shown that the former has a significant effect on the improvement of electrical properties of graphene and other materials. The latter has great potential for development of photodetectors, solar cells, display and other fields. However, the synthesis of these two kinds of materials is not well controlled, and the results are very random, which hinders the further application of two-dimensional heterostructures and other nanocomposite structures. In order to solve the problems in the synthesis of these two-dimensional materials, we choose the semi-metallic graphene, insulator hexagonal boron nitride, topological insulator and semiconductor tungsten disulfide as the research objects, and adopt the chemical vapor deposition method. The controllable synthesis, structure characterization, physical properties measurement and preliminary application of these two dimensional materials have been studied. The results are expected to provide a useful reference for the effective synthesis and scale application of low dimensional nanomaterials. The main results of this paper include the following three aspects: 1. Bi2Se3xTe3 _ (1-x). _ (1-x). Monocrystalline with high quality ternary topological insulating bismuth with layered structure was synthesized on fluorophlogite, silicon / silica substrates by chemical vapor deposition method. The modulation of the microstructure of Bi2Se3xTe3 _ (1-x) was realized by adjusting the concentration of selenium doping, and the samples doped with different selenium were investigated by Raman spectroscopy. The results show that the Raman characteristic peaks of the synthesized Bi2Se3xTe3 _ (1-x) nanocrystals move to the high frequency direction with the increase of selenium doping content and exhibit discontinuous variation characteristics. The results are of reference value for the synthesis of high quality topological insulators and their physical properties. 2. Ultrathin large area graphene film (graphene films). Synthesized by atmospheric pressure and low temperature chemical vapor deposition When the temperature is as low as 500 鈩，

本文編號：2292270