激光沉积法制备掺钴氧化锌稀磁半导体
发布时间：2019-05-29 22:51
【摘要】： 本文中,稀磁半导体(diluted magnetic semiconductor,简称DMS)是指由磁性过渡金属或稀土金属元素(例如:Mn、Fe、Co、Ni、Cr及Eu等)部分替代Ⅱ-Ⅵ族、Ⅳ-Ⅵ族、或Ⅲ-Ⅴ族等半导体中的部分元素后所形成的一类新型半导体材料,同时具有可以调节的电子电荷和电子自旋二种自由度特性。其中磁性离子的3d电子和半导体导带sp电子之间的耦合作用(sp-d)以及磁性离子之间的(d-d)耦合交换作用使得稀磁半导体材料具有很多新颖的磁光和磁电性能,在高密度非易失性存储器、磁感应器、光隔离器、半导体集成电路、半导体激光器和自旋量子计算机等领域有广阔的应用前景。 本文简述了稀磁半导体的历史发展及研究现状,在实验上利用脉冲激光沉积法,首先尝试制备ZnO靶材和薄膜,并以此为基础,成功制备掺钴ZnO靶材和薄膜。通过对材料的光电磁及结构性质测试,研究了材料性质与制备方法和工艺的关系。 论文主要内容包括: (1)利用GCR-170型脉冲激光器Nd:YAG的三次谐波(355nm),以蓝宝石Al2O3 (0001)为衬底,在不同温度下采用脉冲激光沉积法(PLD)制备了ZnO薄膜。通过原子力显微镜(AFM)、Raman谱、光致发光(PL)谱、红外透射谱、霍尔效应和表面粗糙度分析仪对制备的ZnO薄膜进行了测试。分析了在不同衬底温度下薄膜的表面形貌、光学特性,同时进行了薄膜结构和厚度的测试。研究表明:衬底温度对ZnO薄膜的表面形貌、光学特性和结构特性都是重要的工艺参数,尤其在500℃时沉积的ZnO薄膜致密均匀,并表现出较强的紫外发射峰。 (2)在不同的烧结温度下,利用固相反应法制备Zn0.9Co0.1O块体材料,应用单因素实验法对相同的配比成份样品进行处理,并分别对Zn0.9Co0.1O材料进行了X射线能谱(XPS)、M-T、傅立叶红外吸收谱(FTIR)、X射线衍射(XRD)、拉曼图谱(Raman)和光致发光谱(PL)测试和分析。实验结果表明:Co2+掺入ZnO晶格,并很好取代Zn2+的位置而被四面氧所包围,形成了Co-O键。烧结温度对Co掺杂浓度影响不大,排除了形成Co团簇或CoO晶相的可能。烧结温度制约Co2+掺入ZnO晶格,并取代Zn2+的位置而不影响ZnO结构,在1200℃时制备的材料保持了纤锌矿结构,从拉曼光谱中也看到Co2+的声子结构特征明显,并且出现Co离子进入ZnO晶格使得带隙变窄的光学现象。 (3)基于选取不同的基片温度,利用脉冲激光沉积的方法,成功制备出钴掺杂的氧化锌薄膜。通过对制备的样品的原子力显微镜(AFM)测试,观测到生长样品的表面形貌图形较未掺杂ZnO薄膜光滑平整很多;实验上对薄膜的X射线衍射(XRD)表征,测量出Co的掺杂并没有破坏ZnO纤锌矿结构,500℃样品的表面形貌和结构最佳;对薄膜的XPS的分析显示,Co离子在样品中以+2价的形式存在,并随着衬底温度的增加Co的含量也在不断升高,但当温度到达800℃时因超过Co溶解限出现了Co团簇现象。为进一步验证Co离子进入ZnO的晶格,对不同基片温度制备的样品进行透射谱的测量,从全光透射谱看到宽带能隙发生宽化,并讨论了内部机理。同时衬底温度的升高造成结构、价态和含量的变化进而影响了样品的电学和磁学性能,测试发现随着基片温度升高,ZnO掺Co薄膜的载流子浓度和PN型发生明显改变,同时磁学性能随着掺杂浓度呈开口向下的抛物线状。
[Abstract]:In this paper, a thin magnetic semiconductor (DMS) refers to a group consisting of a magnetic transition metal or a rare earth metal element (e.g., Mn, Fe, Co, Ni, Cr and Eu, etc.), Or a class of novel semiconductor materials formed after part of the elements in the semiconductors of the group III-V and the like, and simultaneously has two degrees of freedom of the electronic charge and the electron spin that can be adjusted. in which the coupling effect (sp-d) between the 3d electron of the magnetic ion and the electron of the semiconductor conduction band sp and the (d-d) coupling exchange between the magnetic ions enable the thin magnetic semiconductor material to have a plurality of novel magneto-optical and magneto-electric properties, The optical isolator, the semiconductor integrated circuit, the semiconductor laser and the spin quantum computer have wide application prospect. In this paper, the history development and the research status of the rare-magnetic semiconductors are briefly described. In the experiment, the pulse laser deposition method is used to first attempt to prepare the ZnO target and the thin film, and based on the method, the Co-doped ZnO target is successfully prepared. And the material properties and the preparation method and the process are studied by testing the photoelectromagnetic and structural properties of the materials. The relationship between the two. The main contents of the paper are as follows: (1) The third harmonic (355 nm) of the Nd: YAG laser of the GCR-170 type pulse laser is used, and the sapphire Al2O3 (0001) is used as the substrate, and the pulse laser deposition method is adopted at different temperatures (P The ZnO films were prepared by means of atomic force microscopy (AFM), Raman spectrum, photoluminescence (PL) spectrum, infrared transmission spectrum, Hall effect and surface roughness analyzer. The surface morphology and optical properties of the thin films at different substrate temperatures were analyzed, and at the same time, the surface morphology and optical properties of the films were analyzed. The film structure and thickness are tested. The results show that the surface morphology, optical properties and structural characteristics of ZnO films are important process parameters, especially at 500 鈩，
本文编号：2488289
[Abstract]:In this paper, a thin magnetic semiconductor (DMS) refers to a group consisting of a magnetic transition metal or a rare earth metal element (e.g., Mn, Fe, Co, Ni, Cr and Eu, etc.), Or a class of novel semiconductor materials formed after part of the elements in the semiconductors of the group III-V and the like, and simultaneously has two degrees of freedom of the electronic charge and the electron spin that can be adjusted. in which the coupling effect (sp-d) between the 3d electron of the magnetic ion and the electron of the semiconductor conduction band sp and the (d-d) coupling exchange between the magnetic ions enable the thin magnetic semiconductor material to have a plurality of novel magneto-optical and magneto-electric properties, The optical isolator, the semiconductor integrated circuit, the semiconductor laser and the spin quantum computer have wide application prospect. In this paper, the history development and the research status of the rare-magnetic semiconductors are briefly described. In the experiment, the pulse laser deposition method is used to first attempt to prepare the ZnO target and the thin film, and based on the method, the Co-doped ZnO target is successfully prepared. And the material properties and the preparation method and the process are studied by testing the photoelectromagnetic and structural properties of the materials. The relationship between the two. The main contents of the paper are as follows: (1) The third harmonic (355 nm) of the Nd: YAG laser of the GCR-170 type pulse laser is used, and the sapphire Al2O3 (0001) is used as the substrate, and the pulse laser deposition method is adopted at different temperatures (P The ZnO films were prepared by means of atomic force microscopy (AFM), Raman spectrum, photoluminescence (PL) spectrum, infrared transmission spectrum, Hall effect and surface roughness analyzer. The surface morphology and optical properties of the thin films at different substrate temperatures were analyzed, and at the same time, the surface morphology and optical properties of the films were analyzed. The film structure and thickness are tested. The results show that the surface morphology, optical properties and structural characteristics of ZnO films are important process parameters, especially at 500 鈩，
本文编号：2488289
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