The role of beryllium in the band structure of MgZnO: Lifting the valence band maximum
The role of beryllium in the band structure of MgZnO: Lifting the valence band maximum
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DOI：
10.1063/1.4896683
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发表时间：
2014-09
影响因子：
4
通讯作者：
S. S. Chen-S.;Xinhua Pan;Wenteng Chen;H. H. Zhang-H.;W. Dai;P. Ding;J. Huang;B. Lu;Z. Ye
中科院分区：
文献类型：
--
作者：
S. S. Chen-S.;Xinhua Pan;Wenteng Chen;H. H. Zhang-H.;W. Dai;P. Ding;J. Huang;B. Lu;Z. Ye
通过X射线光电子能谱测量了Mg_xZn_1-−-xO/BexMgyZn-1-−-−-YO异质结的能带偏移量，研究了Be对其价带最大值的影响。采用等离子体辅助分子束外延技术在c面蓝宝石衬底上生长了Mg_xZn_1−_xO和BexMgyZn_1−_x−_yO薄膜。Mg_(0.15)Zn_(0.85)O(Eg=3.62 eV)/B e_(0.005)M_(0.19)Zn_(0.805)O(E_g=3.73 eV)异质结的价带偏移量(ΔeV)为0.01 eV，B e_(0.005)M_(0.19)Zn_(0.805)O的价带偏移量较低。镁含量的增加是VBM降低的主要原因。随着镁含量的增加，随着Eg从3.62 eV增大到3.73 eV，−-xO的VBM降低了0.03 eV。考虑到镁含量增加的影响，当合金的Eg为3.73 eV时，少量的Be使VBM提高0.02 eV。计算得到：Mg0.11Zn0.89O(Eg=3.56 eV)/Be0.007Mg0.12Zn0.873O(Eg=3.56 eV)异质结的ΔEV为0.03 eV，Be0.007Mg0.12Zn0.873O具有较高的Ev.
We investigate the effect of Be on the valence band maximum (VBM) of MgZnO by measuring the band offsets of MgxZn1−xO/BexMgyZn1−x−yO heterojunctions using X-ray photoelectron spectroscopy measurements. MgxZn1−xO and BexMgyZn1−x−yO films have been grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The valence band offset ( ΔEV) of Mg0.15Zn0.85O ( Eg = 3.62 eV)/Be0.005Mg0.19Zn0.805O ( Eg = 3.73 eV) heterojunction is 0.01 eV and Be0.005Mg0.19Zn0.805O has a lower VBM. The increased Mg composition is the main factor for the reduction of VBM. The VBM of MgxZn1−xO is lower by 0.03 eV with the enlargement of Eg from 3.62 eV to 3.73 eV by increasing Mg composition. Considering the effect of increased Mg composition, it is concluded that the little amount of Be makes the VBM go up by 0.02 eV when the Eg of the alloy is 3.73 eV. The ΔEV of Mg0.11Zn0.89O ( Eg = 3.56 eV)/Be0.007Mg0.12Zn0.873O ( Eg = 3.56 eV) heterojunction is calculated to be 0.03 eV and Be0.007Mg0.12Zn0.873O has a higher ...