非补偿n-p共掺杂ZnO薄膜结构和性质的研究

发布时间：2018-03-21 13:04

本文选题：n-p共掺杂　切入点：ZnO薄膜　出处：《山西师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：氧化锌(ZnO)是一种重要的电子信息功能材料。化学性质稳定,原料来源丰富,对环境友好,300 K下大的带隙宽度等优点使得ZnO在发光装置、透明电极等领域有着巨大的应用前景。为了进一步扩大其应用范围,人们经常通过元素掺杂改善其性质,其中非补偿n-p共掺杂就是一种有效的掺杂方法。相对于元素单掺杂,非补偿n-p共掺杂不但可以提高元素固溶度,使ZnO获得磁性,避免团簇和第二相磁性杂质相的出现,还可以有效的调节其带隙,改善其电学性能。本论文以V/N和Cr/N为非补偿n-p共掺对,采用脉冲激光沉积技术制备了一系列掺杂ZnO薄膜,系统的研究了V/N和Cr/N共掺杂对ZnO薄膜结构、输运、磁性和光学性质的的影响。主要研究内容如下:(1)采用脉冲激光沉积技术在Al_2O_3(0001)基片上制备了一系列Zn_(1-x)V_xO和Zn_(1-x)V_xO/N(x=0,0.01,0.03,0.06)晶体薄膜,通过对比不同掺杂量对薄膜各性能的影响,阐释了非补偿n-p共掺杂在调控ZnO薄膜输运、磁性和光学带隙方面所发挥的优势与作用。研究结果表明,薄膜样品结晶性良好,ZnO(002)面为主要晶面,没有检测到V金属团簇及其氧化物。与N单掺杂相比,V/N共掺杂能够有效增加N在ZnO基体中的固溶度,并且V在高掺杂含量时以V~(3+)和V~(4+)存在,在低掺杂含量时主要以V~(4+)存在。Hall测试表明薄膜均为n型半导体,Zn VO薄膜的载流子浓度可达1020cm-3,由于NO的补偿作用,ZnVO/N薄膜的载流子浓度降至1019 cm-3,但仍大于纯ZnO的载流子浓度。ZnVO/N比ZnVO薄膜有着更大的室温饱和磁矩,其磁性同时受载流子浓度和氧空穴的调节。薄膜的光学带隙与载流子浓度有关,在薄膜内可能发生了Burstein-Moss效应。(2)利用脉冲激光沉积方法制备了一系列Zn_(1-x)Cr_x O和Zn_(1-x)Cr_x O/N(x=0,0.05,0.10)纳米薄膜,研究了Cr/N共掺杂对ZnO薄膜结构、磁性及光学性质的影响。结构测试表明薄膜样品均为单相纤锌矿结构,且沿c轴垂直取向生长。Cr以Cr~(3+)离子存在于ZnO中的取代位,而N则几乎没能够有效的进入ZnO晶格中的取代位。ZnCrO和ZnCrO/N薄膜均显示一定的室温铁磁性,在Cr、N掺杂含量合适的情况下,ZnCrO/N薄膜可获得最大的室温饱和磁化强度,其铁磁性与薄膜内存在的氧空穴浓度有一定的关系。Cr/N共掺杂比Cr单掺杂和N单掺杂更能有效增大ZnO薄膜的带隙,其变化受晶粒尺寸的影响。总之,我们沉积了一系列Zn VO/N和ZnCrO/N薄膜样品,成功的实现了对ZnO稀磁半导体薄膜载流子浓度、磁性和带隙的调控,这有助于ZnO半导体材料在未来电子器件中的发展及应用。
[Abstract]:Zinc oxide (ZnO) is an important electronic information functional material. The advantages of stable chemical properties, abundant source of raw materials, and large band gap width at 300K make ZnO luminescent devices. Transparent electrodes and other fields have great application prospects. In order to further expand the scope of their applications, people often improve their properties by doping elements, in which uncompensated n-p co-doping is an effective doping method. Uncompensated n-p co-doping can not only improve the solid solubility of element, make ZnO obtain magnetism, avoid the appearance of cluster and second phase magnetic impurity phase, but also adjust its band gap effectively. In this thesis, a series of doped ZnO thin films were prepared by pulsed laser deposition using V / N and Cr/N as uncompensated n-p co-doped pairs. The structure and transport of V / N and Cr/N co-doped ZnO films were systematically studied. The effects of magnetic and optical properties. The advantages and functions of uncompensated n-p co-doping in regulating the transport, magnetic and optical band gap of ZnO thin films are explained. No V metal clusters and their oxides were detected. Compared with N mono-doping, V / N co-doping can effectively increase the solubility of N in the ZnO matrix, and V exists in the presence of V _ (3) and V _ ((4)) at high doping content. Hall measurements show that the carrier concentration of n-type semiconductor ZnVO thin films can reach 1020cm-3, and the carrier concentration of ZnVO/ N thin films decreases to 1019cm-3 due to the compensatory effect of no, but it is still larger than that of pure ZnO films. The flux concentration. ZnVO / N has a larger saturation magnetic moment at room temperature than the ZnVO thin film. The magnetic properties are regulated by both carrier concentration and oxygen hole. The optical band gap is related to carrier concentration. The Burstein-Moss effect may occur in the film. (2) A series of Zn_(1-x)Cr_x O and Zn_(1-x)Cr_x O / NX / NX 0. 05% 0. 10) nanocrystalline films have been prepared by pulsed laser deposition. The effects of Cr/N co-doping on the structure, magnetic and optical properties of ZnO thin films were investigated. The results showed that the films were all single-phase wurtzite structures, and the perpendicular orientation of .Cr along the c-axis was the substitution of Cr~(3 ions in ZnO. On the other hand, the substitution sites. ZnCrO and ZnCrO/N films in ZnO lattice can hardly show room temperature ferromagnetism, and the maximum room temperature saturation magnetization can be obtained under the condition of the proper doping content of CrN in ZnCrO / N thin films. There is a certain relationship between the ferromagnetism and the oxygen hole concentration in the films. The Cr / N co-doping can increase the band gap of ZnO films more effectively than Cr mono-doping and N-mono-doping, and the changes are affected by the grain size. We have deposited a series of Zn VO/N and ZnCrO/N thin film samples, which have successfully controlled the carrier concentration, magnetism and band gap of ZnO thin film, which is helpful to the development and application of ZnO semiconductor materials in electronic devices in the future.
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ132.41;TB383.2

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