中国物理B ›› 2017, Vol. 26 ›› Issue (3): 37101-037101.doi: 10.1088/1674-1056/26/3/037101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Electrical property effect of oxygen vacancies in the heterojunction of LaGaO3/SrTiO3

Fu-Ning Wang(王芙凝), Ji-Chao Li(李吉超), Xin-Miao Zhang(张鑫淼), Han-Zhang Liu(刘汉璋), Jian Liu(刘剑), Chun-Lei Wang(王春雷), Ming-Lei Zhao(赵明磊), Wen-Bin Su(苏文斌), Liang-Mo Mei(梅良模)   

  1. School of Physics, Shandong University, Jinan 250100, China
  • 收稿日期:2016-11-10 修回日期:2016-12-27 出版日期:2017-03-05 发布日期:2017-03-05
  • 通讯作者: Ji-Chao Li E-mail:lijichao@sdu.edu.cn
  • 基金资助:

    Project supported by the National Basic Research Program of China (Grant No. 2013CB632506) and the National Natural Science Foundation of China (Grant Nos. 11374186, 51231007, and 51202132).

Electrical property effect of oxygen vacancies in the heterojunction of LaGaO3/SrTiO3

Fu-Ning Wang(王芙凝), Ji-Chao Li(李吉超), Xin-Miao Zhang(张鑫淼), Han-Zhang Liu(刘汉璋), Jian Liu(刘剑), Chun-Lei Wang(王春雷), Ming-Lei Zhao(赵明磊), Wen-Bin Su(苏文斌), Liang-Mo Mei(梅良模)   

  1. School of Physics, Shandong University, Jinan 250100, China
  • Received:2016-11-10 Revised:2016-12-27 Online:2017-03-05 Published:2017-03-05
  • Contact: Ji-Chao Li E-mail:lijichao@sdu.edu.cn
  • Supported by:

    Project supported by the National Basic Research Program of China (Grant No. 2013CB632506) and the National Natural Science Foundation of China (Grant Nos. 11374186, 51231007, and 51202132).

摘要:

Density functional theory within the local density approximation is used to investigate the effect of the oxygen vacancy on the LaGaO3/SrTiO3 (001) heterojunction. It is found that the energy favorable configuration is the oxygen vacancy located at the 3rd layer of the STO substrate, and the antiferrodistortive distortion is induced by the oxygen vacancy introduced on the SrTiO3 side. Compared with the heterojunction without introducing oxygen vacancy, the heterojunction with introducing the oxygen vacancy does not change the origin of the two-dimensional electron gas (2DEG), that is, the 2DEG still originates from the dxy electrons, which are split from the t2g states of Ti atom at interface; however the oxygen vacancy is not beneficial to the confinement of the 2DEG. The extra electrons caused by the oxygen vacancy dominantly occupy the 3dx2-y2 orbitals of the Ti atom nearest to the oxygen vacancy, thus the density of carrier is enhanced by one order of magnitude due to the introduction of oxygen vacancy compared with the density of the ideal structure heterojunction.

关键词: two-dimensional electron gas (2DEG), first-principles calculation, oxygen vacancy

Abstract:

Density functional theory within the local density approximation is used to investigate the effect of the oxygen vacancy on the LaGaO3/SrTiO3 (001) heterojunction. It is found that the energy favorable configuration is the oxygen vacancy located at the 3rd layer of the STO substrate, and the antiferrodistortive distortion is induced by the oxygen vacancy introduced on the SrTiO3 side. Compared with the heterojunction without introducing oxygen vacancy, the heterojunction with introducing the oxygen vacancy does not change the origin of the two-dimensional electron gas (2DEG), that is, the 2DEG still originates from the dxy electrons, which are split from the t2g states of Ti atom at interface; however the oxygen vacancy is not beneficial to the confinement of the 2DEG. The extra electrons caused by the oxygen vacancy dominantly occupy the 3dx2-y2 orbitals of the Ti atom nearest to the oxygen vacancy, thus the density of carrier is enhanced by one order of magnitude due to the introduction of oxygen vacancy compared with the density of the ideal structure heterojunction.

Key words: two-dimensional electron gas (2DEG), first-principles calculation, oxygen vacancy

中图分类号:  (Electron gas, Fermi gas)

  • 71.10.Ca
63.20.dk (First-principles theory) 61.72.jd (Vacancies)