LDH前驱体热解法构筑掺杂氧化物体系及其光电应用研究
发布时间：2019-04-28 18:18
【摘要】：NiO、ZnO和(Zn,Ga)(N,O)一直是科研界广受关注的化合物半导体材料,利用其特点人们开发了多种光电磁应用。而异价掺杂是一种有效的调控和改善此类半导体材料中的晶体微结构,以及电学性质(载流子密度,迁移率),光学性质(光吸收,发光),磁性质等的重要手段。在目前掺杂半导体的工艺中往往采取磁控溅射、固相掺杂等物理方法,但是这些物理方法普遍存在掺杂元素分布不均、工艺复杂,成本高等的问题。化学掺杂使基于水溶液体系的共沉淀方法进行掺杂,具有条件温和,掺杂均匀等特点。LDH作为双金属复合层状氢氧化物,具有金属元素分布均匀的特点,以其为前驱体制备金属掺杂氧化物将是极佳的选择。据此本论文提出利用元素分布均匀的LDH前驱体,通过热解得到均匀掺杂产物,并对其进行光电性能测试,对于发展化学掺杂半导体的方法有重要学术意义。本文利用三种LDH前驱体热解法分别构筑了均匀掺杂的NiO:Al、 ZnO:Al以及(Zn,Ga)(O,N)等三个研究体系,并利用SEM、XRD、TEM、 HRTEM、STEM、EXAFS等手段对其物相结构和形貌进行了表征。采用旋涂-热解法制备了纳米薄膜材料,并对其进行了光学和电化学等测试。Ni-Al LDH的高温(500 ℃C以上)热解产物在XRD中显示只有NiO:Al呈结晶相。铝的掺杂能引起NiO的晶格收缩,并增大氧化镍的比表面积以利于电子在材料中的传导。采用前驱物旋涂-热解法制备了NiO:Al薄膜,研究了NiO:Al薄膜的电化学性质,并运用了计时电流法研究电致变色膜的变色速率(CA),测定其光学透过率。由测试结果表明铝离子含量的不同会影响薄膜的光学和电化学性能,电致变色性能结果表明以19:1 Ni-Al LDH为前驱体制备的电致变色薄膜的变色速率快(漂白速度1.8 s,着色速度4.2s),光学调制范围较大(58%,漂白态透过率可达96%),循环稳定好(200次循环调制范围只减少15%)。采用Zn-Al LDH热解法同样制备了均匀ZnO:Al,并通过样品粉末的电阻率和旋涂薄膜的固体紫外测试研究其透明导电性能。由于Zn-Al LDH阳离子可调范围小于Ni-Al LDH,所以该方法制备的ZnO:Al中的铝含量过高导致制备产品电阻较大。而对于(Ga,Zn)(O,N)我们研究了其在氨气氛围中的制备条件,结果表明通过锌镓水滑石前驱体热解法成功制备了均匀掺镓氮氧化锌,并研究了通过调控阳离子投料比例来制备不同镓比例的(Ga,Zn)(O,N),最后研究了它的光电催化和光催化降解甲基橙性能,结果发现该固溶体对于降解甲基橙效果良好。总之,通过LDH前驱体热解法我们成功制备了均匀掺杂的氧化镍、氧化锌和氮氧化锌粉体及薄膜材料,通过控制三价金属离子浓度,实现了不同掺杂浓度的NiO:Al, ZnO:Al和(Ga,Zn)(O,N),并探索了这些均匀掺杂体系在光电方面的潜在应用。
[Abstract]:NiO,ZnO and (Zn,Ga) (N, O) have been widely concerned about compound semiconductor materials in the field of scientific research. Many kinds of optical and electromagnetic applications have been developed according to their characteristics. Heterovalent doping is an effective means to control and improve the crystal microstructure, as well as electrical properties (carrier density, mobility), optical properties (optical absorption, luminescence), magnetic properties and so on. At present, magnetron sputtering, solid-state doping and other physical methods are often adopted in the process of doping semiconductors. However, there are many problems in these physical methods, such as uneven distribution of doping elements, complex process and high cost. Chemical doping makes the co-precipitation method based on aqueous solution have the characteristics of mild conditions and uniform doping. As a bimetallic composite layered hydroxide, LDH has the characteristics of uniform distribution of metal elements. It would be an excellent choice to prepare metal-doped oxides by precursor system. In this paper, it is proposed that the uniformly doped products can be obtained by pyrolysis of LDH precursors with uniform element distribution, and the optical and electrical properties of the products are tested, which is of great academic significance for the development of chemically doped semiconductors. In this paper, three research systems of uniformly doped NiO:Al, ZnO:Al and (Zn,Ga) (O, N) have been constructed by using three kinds of LDH precursor pyrolysis methods, and SEM,XRD,TEM, HRTEM,STEM, has been used. The phase structure and morphology were characterized by EXAFS. Nano-film materials were prepared by spin-coating-pyrolysis method and tested by optical and electrochemical methods. The pyrolysis products of Ni-Al LDH at high temperature (over 500 鈩，
本文编号：2467853
[Abstract]:NiO,ZnO and (Zn,Ga) (N, O) have been widely concerned about compound semiconductor materials in the field of scientific research. Many kinds of optical and electromagnetic applications have been developed according to their characteristics. Heterovalent doping is an effective means to control and improve the crystal microstructure, as well as electrical properties (carrier density, mobility), optical properties (optical absorption, luminescence), magnetic properties and so on. At present, magnetron sputtering, solid-state doping and other physical methods are often adopted in the process of doping semiconductors. However, there are many problems in these physical methods, such as uneven distribution of doping elements, complex process and high cost. Chemical doping makes the co-precipitation method based on aqueous solution have the characteristics of mild conditions and uniform doping. As a bimetallic composite layered hydroxide, LDH has the characteristics of uniform distribution of metal elements. It would be an excellent choice to prepare metal-doped oxides by precursor system. In this paper, it is proposed that the uniformly doped products can be obtained by pyrolysis of LDH precursors with uniform element distribution, and the optical and electrical properties of the products are tested, which is of great academic significance for the development of chemically doped semiconductors. In this paper, three research systems of uniformly doped NiO:Al, ZnO:Al and (Zn,Ga) (O, N) have been constructed by using three kinds of LDH precursor pyrolysis methods, and SEM,XRD,TEM, HRTEM,STEM, has been used. The phase structure and morphology were characterized by EXAFS. Nano-film materials were prepared by spin-coating-pyrolysis method and tested by optical and electrochemical methods. The pyrolysis products of Ni-Al LDH at high temperature (over 500 鈩，
本文编号：2467853
本文链接：https://www.wllwen.com/kejilunwen/cailiaohuaxuelunwen/2467853.html
