本文選題：納米線陣列 + Type-Ⅱ型能帶結(jié)構(gòu)��； 參考：《湘潭大學(xué)》2015年碩士論文

【摘要】：近年來,越來越多的人開始研究新型的太陽能轉(zhuǎn)換設(shè)備,納米材料和納米結(jié)構(gòu)的引入對其性能的提高展現(xiàn)了至關(guān)重要的作用。許多一維納米結(jié)構(gòu)被用于光伏器件的制備,這些結(jié)構(gòu)中最為常見的有納米線和納米管。這是因?yàn)樗鼈兝硐氲膸缀谓Y(jié)構(gòu)能夠?yàn)殡娮拥妮斶\(yùn)提供直接通道。相比于薄膜材料,一維納米材料在可以光光譜范圍內(nèi)對光有更低的反射率,因而具有更優(yōu)良的光吸收特性。ZnO納米線陣列因其溫和的合成方法和優(yōu)越的光學(xué)性質(zhì)被大量用于光伏器件。然而,Zn O的帶隙比較大(室溫下E=3.37eV),不能夠有效的吸收和利用太陽光可見光區(qū)域的能量。為了通過可見光激發(fā)生成更多的電子-空穴對,很多研究將窄帶隙的材料負(fù)載在ZnO納米線上,在這些敏化材料中,CdS和CdSe是最常用的兩種可見光敏化半導(dǎo)體。在本文中,我們主要以ZnO和TiO2/ZnO納米線陣列為基礎(chǔ),通過具有不同帶隙的硫?qū)倩衔?如ZnSe,CdS和CdSe)將其多重敏化,以提高復(fù)合電極材料可見光區(qū)的光吸收能力,最后達(dá)到促進(jìn)其光電化學(xué)制氫性能的效果。論文的主要內(nèi)容如下:1.首先,我們使用水熱法、離子交換方法以及連續(xù)的化學(xué)浴沉積方法在FTO導(dǎo)電玻璃基底上合成ZnSe/CdS/CdSe三重敏化的ZnO納米線陣列結(jié)構(gòu)用于多帶隙制氫。離子交換方法和化學(xué)浴沉積方法能夠很好地控制敏化層的厚度,這些敏化層的厚度將直接影響所合成異質(zhì)結(jié)構(gòu)的可見光吸收能力以及它們的光電化學(xué)性能。實(shí)驗(yàn)發(fā)現(xiàn),通過ZnO納米線陣列和各敏化層之間的協(xié)同光吸收作用以及它們之間連續(xù)階梯式type-Ⅱ型能帶結(jié)構(gòu)排列,我們制備出來的ZnO@ZnSe/CdS/CdSe復(fù)合陣列光電極的光電化學(xué)制氫性能相對簡單的ZnO納米線陣列以及其它復(fù)合光電極(如:ZnO@ZnSe和ZnO@ZnSe/CdS)有不同程度的提高。當(dāng)測試偏壓為0V時(shí)(vs.Ag/AlCl),ZnO@ZnSe/CdS/CdSe納米線陣列光電極的飽和光電流密度達(dá)到5.3 mA/cm2,遠(yuǎn)大于ZnO@ZnSe(1.1 mA/cm2)和ZnO@ZnSe/CdS(2.6 mA/cm2)納米線陣列光電極的電流密度,是純ZnO納米線陣列光電極電流密度大小的12倍。2.另外,在FTO導(dǎo)電玻璃上合成CdS/CdSe共敏化的疊層TiO2/ZnO納米線陣列,并用于光電化學(xué)制氫。具體過程是,先在FTO上通過水熱法生長TiO2納米線陣列,隨后以其為基底再生長一層ZnO納米線陣列。為了進(jìn)一步提高TiO2/ZnO的可見光吸收能力,我們依次通過窄帶隙的CdS和CdSe量子點(diǎn)將其敏化。光電化學(xué)性能測試結(jié)果發(fā)現(xiàn),當(dāng)測試偏壓為0V時(shí)(vs.Ag/AlCl),TiO2/ZnO@CdS/CdSe納米線陣列光電極的光電流密度達(dá)到了9.8 mA/cm2,是TiO2/ZnO@CdS納米線陣列的1.5倍。此外,在偏壓為0.6V時(shí)(vs.Ag/AlCl),TiO2/ZnO@CdS/CdSe納米線陣列光電極的飽和光電流密度達(dá)到11.5 mA/cm2。
[Abstract]:In recent years, more and more people began to study new solar energy conversion equipment. The introduction of nano-materials and nanostructures has shown a crucial role in improving their performance. Many one-dimensional nanostructures are used to fabricate photovoltaic devices, the most common of which are nanowires and nanotubes. This is because their ideal geometry can provide direct channels for the transport of electrons. Compared with thin film materials, one-dimensional nanomaterials have lower reflectivity to light in the range of light spectrum. ZnO nanowire arrays are widely used in photovoltaic devices because of their mild synthesis methods and superior optical properties. However, the band gap of Zno is relatively large (E ~ (3. 37) EV ~ (2 +) at room temperature, which can not effectively absorb and utilize the energy in the visible region of solar light. In order to generate more electron-hole pairs by excitation of visible light, many studies have carried narrow band gap materials onto ZnO nanowires. Among these sensitized materials, CDs and CdSe are the two most commonly used visible Guang Min semiconductors. In this paper, we mainly use ZnO and TiO2/ZnO nanowire arrays as the basis to increase the optical absorption ability of the composite electrode materials in the visible region by the multiple sensitization of sulfur compounds with different band gaps (such as ZnSee, CDs and CdSee). Finally, the effect of promoting its photochemical hydrogen production performance is achieved. The main contents of the thesis are as follows: 1: 1. Firstly, ZnSe/CdS/CdSe triple sensitized ZnO nanowire arrays were synthesized on FTO conductive glass substrate by hydrothermal method, ion exchange method and continuous chemical bath deposition method. Ion exchange method and chemical bath deposition method can control the thickness of the sensitized layer. The thickness of these sensitized layers will directly affect the visible light absorption ability of the synthesized heterostructures and their photochemical properties. The experimental results show that the ZnO nanowire array and the sensitized layers have synergistic optical absorption, and the continuous type 鈪，

本文編號(hào)：1905592