摘要
采用直流反应磁控溅射的方法,在玻璃衬底上沉积了Zn0.93Mn0.07O薄膜,研究了氧分压对薄膜结构和光学特性的影响。X射线衍射测试结果显示,Zn0.93Mn0.07O薄膜都具有高度的c轴择优取向,在氧分压为0.4的时候,薄膜的衍射峰具有最小的半峰全宽,最大的晶粒尺寸。X射线光电子能谱测试结果表明:Mn2 +离子已经取代了氧化锌晶格中的部分Zn2 +,但还掺杂有少量的MnO2分子;处在1 021 eV的Zn 2p3/2能级只有单一的Zn2 +;而O2 -则来自Zn-O和Mn-O。由于伯斯坦-莫斯效应,Zn0.93Mn0.07O薄膜光吸收跃迁过程只能在价带态和费密能级附近及以上的导带空态之间发生,其吸收谱线显示,与纯ZnO薄膜吸收谱线相比,产生了蓝移现象。同时还伴随有导带尾跃迁的发生,研究表明,这是由3d5多重能级的d-d跃迁而引起的。经过计算,在氧分压为0.4的时,Zn0.93Mn0.07O薄膜的禁带宽度是最大的,这可能是由交换作用的减弱而引起的。
The Zn1-xMnxO（x = 0.07） thin films were grown on glass by direct current （dc） magnetron sputtering, and the influences of oxygen partial pressure on crystallization behavior as well as on optical properties of ZnI1-xMnxO films were investigated. X-ray diffraction （XRD） results indicate that the films are highly c-axis oriented, especially at the ambient of oxygen partial pressure of 0.4. When R is 0.4, there are the smallest full width at half maximum （FWHM） of the diffraction peak and the biggest grain size. The lattice parameter c of the ZnI1-xMnxO thin films is larger than that of ZnO film. The optical transmission spectra show that the absorption is the largest when R is 0.4. X-ray photoelectron spectroscopy （XPS） results show ： 1. the two peaks at 640.7 and 652.3 eV are in agreement with the binding energy of Mn 2p3/2 and Mn 2pl/2 without other XPS signals, indicating the coexistence of small amounts of Mn^2＋ and MnO2. 2. the binding energy of Zn 2p3/2 is 1 021.7 eV with a narrow linewidth of 1.86 eV, implying only a single component of Zn^2＋ ions. 3. the two narrow peaks at 530.1 and 532.0 eV, the former may be attributed to 05- ions in Zn-O and Mn-O bonds, while another is associated with the loosely bound oxygen chemi- sorbed on the surface and/or grain boundary of polycrystalline film. The quantitative analysis indicates that the atom fraction of Mn doped in film is 7.3 % （ Zn0 93 Mn0.07 O）. Owing to Burstein-Moss （ B-M ） effect, the absorption spectra show that the blue-shift absorption edge transition happens between valence band level and near or above the Fermi level, while the absorption band tailing is attributed to the d-d transitions of tetrabedral Mn^2＋ between the crystal- field-split 3d5 muhiplet levels. When x is sure, the band-gap energy is the largest at R being 0.4 by calculation. It can be interpreted when the alloy enters the antiferromagnetic or spin-glass phase, the effect of the exchange interac- tion decreases, in turn removing this red shift, and producing an apparent additional blue shift of the energy gap at low temperatures and oxygen partial pressure below 0.4.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2007年第6期875-879,共5页
Chinese Journal of Luminescence
基金
国家自然科学基金(60571043)
中南大学研究生教育创新基金(062510029)资助项目~~
关键词
锰掺杂氧化锌薄膜
溅射
光学性能
Mn-doped ZnO thin films
sputtering
optical properties
