本文選題：非極性ZnO + NiO(111)/ZnO(1120)異質結�。� 參考：《浙江大學》2014年碩士論文

【摘要】：外延ZnO薄膜大多數沿著c軸方向擇優(yōu)生長,沿著c軸方向生長的ZnO薄膜,鋅原子層與氧原子層交替排列,由于缺少反演對稱性,從而導致了很強的晶格自發(fā)極化效應,降低了ZnO基器件的效率。使ZnO材料沿著非極性或半極性方向生長可避免或削弱晶格極化效應造成的不良影響。另一方面,制備高質量的p型ZnO材料仍是一世界性研究難題,這極大程度上阻礙了ZnO同質pn結器件的發(fā)展。作為一種選擇性方案,采用p型材料與n型ZnO制備異質結開始受到了關注。 本文采用脈沖激光沉積系統(tǒng)(PLD),制備了不同Li含量的LixNi1-xO薄膜、高質量的非極性ZnO薄膜、不同結構的p-NiO(111)/n-Zn0(1120)異質結和Mg0.2Ni0.8O/ZnO異質結。研究了生長參數對LixNi1-xO薄膜性能的影響、p-NiO(111)/n-ZnO(1120)異質結的性能和Mg0.2Ni0.8O/ZnO異質結的能帶結構。具體工作如下： 1、在石英襯底上制備了LiXNi1-xO薄膜,研究了生長參數對制備的LixNi1-xO薄膜性能的影響,結果表明沉積壓強和襯底溫度對薄膜的晶體質量、光學性能、電學性能有較大影響。在350℃,5Pa的條件下制備的LixNi1-xO薄膜的綜合性能較佳。 2、參考在石英襯底上制備LixNi1-xO薄膜的實驗結果,我們在r面藍寶石上制備了兩種不同結構的p-NiO(111)/n-ZnO(1120)異質結,通過改變Lio.07Ni0.93O薄膜的沉積壓強,并在NiO與ZnO之間插入MgZnO中間層,獲得了性能較好的異質結。 3、在上述工作的基礎上,制備了禁帶寬度大于NiO的MgNiO薄膜。采用X射線光電子能譜法研究了Mgo.2Nio.80(111)/ZnO異質結中ZnO的生長取向對于異質結價帶帶階的影響。Mgo.2Nio.80(111)/ZnO(1120)和Mgo.2Ni0.80(111)/ZnO(0002)兩種異質結的價帶帶階分別為1.8±O.1eV和1.4±0.1eV,導帶帶階為2.4±0.1eV和2.0±0.1eV。兩種異質結都呈現type-Ⅱ能帶結構,兩種異質結能帶結構的差異主要原因是在極性ZnO中存在自發(fā)極化效應。
[Abstract]:Most of the epitaxial ZnO thin films have preferred growth along the c-axis, and the ZnO films grown along the c-axis have alternating arrangement of zinc atomic layer and oxygen atomic layer. Due to the lack of inversion symmetry, the lattice spontaneous polarization effect is very strong. The efficiency of ZnO based devices is reduced. The negative effects of lattice polarization can be avoided or weakened by the growth of ZnO materials along non-polar or semi-polar directions. On the other hand, the preparation of high quality p-type ZnO materials is still a worldwide research problem, which greatly hinders the development of ZnO homogenous pn-junction devices. As a selective scheme, the preparation of heterojunctions using p-type materials and n-type ZnO has attracted more and more attention. In this paper, LixNi1-xO thin films with different Li content, high quality nonpolar ZnO thin films, p-NiON 111 / n-Zn0N1120) heterostructures and Mg0.2Ni0.8O/ZnO heterostructures have been prepared by pulsed laser deposition system. The effects of growth parameters on the properties of LixNi1-xO thin films were investigated. The properties of p-NiO / n-ZnO (1120) heterostructures and the band structure of Mg0.2Ni0.8O/ZnO heterostructures were investigated. The specific work is as follows: 1. LiXNi1-xO thin films were prepared on quartz substrates. The effects of growth parameters on the properties of LixNi1-xO thin films were studied. The results show that the deposition pressure and substrate temperature have great influence on the crystal quality, optical properties and electrical properties of the films. The LixNi1-xO films prepared at 350 鈩，

本文編號：1809039