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

【摘要】：外延ZnO薄膜大多數(shù)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(dǎo)致了很強的晶格自發(fā)極化效應(yīng),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(yīng)造成的不良影響。另一方面,制備高質(zhì)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(zhì)pn結(jié)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(zhì)結(jié)開始受到了關(guān)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(zhì)量的非極性ZnO薄膜、不同結(jié)構(gòu)的p-NiO(111)/n-Zn0(1120)異質(zhì)結(jié)和Mg0.2Ni0.8O/ZnO異質(zhì)結(jié)。研究了生長參數(shù)對LixNi1-xO薄膜性能的影響、p-NiO(111)/n-ZnO(1120)異質(zhì)結(jié)的性能和Mg0.2Ni0.8O/ZnO異質(zhì)結(jié)的能帶結(jié)構(gòu)。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(shù)對制備的LixNi1-xO薄膜性能的影響,結(jié)果表明沉積壓強和襯底溫度對薄膜的晶體質(zhì)量、光學(xué)性能、電學(xué)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(jié)果,我們在r面藍(lán)寶石上制備了兩種不同結(jié)構(gòu)的p-NiO(111)/n-ZnO(1120)異質(zhì)結(jié),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(zhì)結(jié)。 3、在上述工作的基礎(chǔ)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(zhì)結(jié)中ZnO的生長取向?qū)τ诋愘|(zhì)結(jié)價帶帶階的影響。Mgo.2Nio.80(111)/ZnO(1120)和Mgo.2Ni0.80(111)/ZnO(0002)兩種異質(zhì)結(jié)的價帶帶階分別為1.8±O.1eV和1.4±0.1eV,導(dǎo)帶帶階為2.4±0.1eV和2.0±0.1eV。兩種異質(zhì)結(jié)都呈現(xiàn)type-Ⅱ能帶結(jié)構(gòu),兩種異質(zhì)結(jié)能帶結(jié)構(gòu)的差異主要原因是在極性ZnO中存在自發(fā)極化效應(yīng)。
[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