Electronic Structure and Electrical Properties of Mg-Substituted ZnO Oxide
-
摘要: 采用密度泛函理论平面波超软赝势广义梯度近似方法，系统研究了Mg置换的ZnO基氧化物的晶格结构和电子结构，在此基础上分析了置换氧化物的电学性能。计算分析结果表明：Mg置换后的ZnO基氧化物其晶格减小，仍为直接带隙材料，带宽1.2 eV。Mg掺杂ZnO体系主要在-40 eV能量附近产生新的能带。费米能级附近的能带主要由Mg p、Zn p、Zn d、O p、Mg s、Zn s、O s电子形成，且这些能带之间存在着强相互作用。Zn p、Zn d、O p电子形成的能级上的载流子在外场作用下首先迁移至Mg s电子形成的能级，形成电输运过程。置换体系费米能级附近的载流子有效质量、态密度和载流子浓度都大大提高；Mg置换有利于ZnO材料体系电导率的提高。Abstract: The lattice structure, electronic sructure and electrical properies of the Mg doped ZnO have been systematically investigated by the ultro-soft pseudo-potentials based on the density functional theory calculations under the generallized gradient approximation.The calculational and analyzing results show the shrinked lattice and the increased direct band gap of 1.2 eV of the Mg doped ZnO system.There are newly formed bands near the -40 eV.The bands near Fermi level are composed by the Mgp, Zn p, Zn d, O p, Mg s, Zn s, O s electrons and strong hybridizations between them are found.The carriers of the bands formed by Zn p, Zn d, O p electrons hop to the bands formed by the s, and then the electrical conduction is accomplished.The carrier effective mass, density of states as well as the carrier concentration near Fermi level are increased for the Mg doped system.The electrical conductivity should be enhanced by Mg doping for ZnO.
-
Key words:
- ZnO oxide /
- Mg doping /
- electronic structures /
- electrical properties
-
图 1 计算采用的ZnO晶胞结构模型
Figure 1. ZnO cell structure model used in the calculation
(a) ZnO (b) MgZn7O8
图 3 计算所得ZnO和Mg置换ZnO的总态密度
Figure 3. Calculated total density of states
(a) ZnO (b) MgZn7O8
表 1 未置换ZnO和Mg置换ZnO基氧化物的晶格参数
Table 1. Lattice parameters for the un-doped ZnO and Mg doped ZnO
Compound a/(nm) b/(nm) c/(nm) ZnO 0.650 94 0.650 94 0.524 92 Mg doped ZnO 0.649 73 0.649 73 0.522 82 
下载: 导出CSV
表 2 Mg置换ZnO的原子组成电子电荷分布
Table 2. Charge populations for elements of Mg doped ZnO
Element s p d Total charge O 1.85 4.99 0.00 -0.84e Zn 0.47 0.71 9.98 0.84e Element s p d Total charge O 1.85/1.88 5.01/5.10/5.11 0.00 -0.85e/0.86e/0.98e/0.99e Mg 0.37 5.73 0.00 1.90e Zn 0.47/0.49/0.50 0.69/0.77/0.78 9.97e 0.76e/0.78e/0.84e
下载: 导出CSV
-
[1] Shin E H, Kim H. Atomic and electronic structures of ZnO Divacancy in hexagonal ZnO[J]. J Korean Phys Sci, 2014, 64(4): 543-546. doi: 10.3938/jkps.64.543 [2] Özgürü, Alivov Y I, Liu C, et al. A comprehensive review of ZnO materials and devices[J]. J Appl Phys, 2005, 98: 041301. doi: 10.1063/1.1992666 [3] Wang X B, Li D M, Zeng F. Microstructure and properties of Cu-doped ZnO films prepared by dc reactive magnetron sputtering[J]. J Phys D: Appl Phys, 2005, 38: 4104. doi: 10.1088/0022-3727/38/22/014 [4] Yang Y C, Song C, Wang X H. Giant piezoelectric d33 coefficient in ferroelectric vanadium doped ZnO films[J]. Appl Phys Lett, 2008, 92: 012907. doi: 10.1063/1.2830663 [5] Qu X, Wang W, Lü S, et al. Thermoelectric properties and electronic structure of Al-doped ZnO[J]. Solid State Commun, 2011, 151(4): 332-336. doi: 10.1016/j.ssc.2010.11.020 [6] Ohtaki M, Tsubota T, Eguchi K. High temperature thermoelectric properties of(Zn1-xAlx)O[J]. J Appl Phys, 1996, 79(3): 1816-1818.. doi: 10.1063/1.360976 [7] Park K, Ko K Y. Effect of TiO2 on high-temperature thermoelectric properties of ZnO[J]. J Alloys Compd, 2007, 430(1/2): 200-204. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=0de94917a08ec53e8c8c34e7d6f2cadb [8] 张飞鹏, 曾宏, 路清梅, 等. ZnO氧化物的电子结构和热学性能[J].功能材料与器件学报, 2013, 19(2): 63-68. http://www.cqvip.com/QK/94788A/20132/1002053110.htmlZhang F P, Zeng H, Lu Q M, et al. Electronic structure and thermal properties of ZnO oxide[J]. Journal of Functional Materials and Devices, 2013, 19(2): 63-68. (in Chinese) http://www.cqvip.com/QK/94788A/20132/1002053110.html [9] 韦金明, 张飞鹏, 张久兴. Cu掺杂对ZnO氧化物电子结构与电输运性能的影响[J].量子电子学报, 2014, 31(3): 372-378. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=lzdzxb201403019Wei J M, Zhang F P, Zhang J X. Effects of Cu doping on electronic structure and electrical transport properties of ZnO oxide[J]. Chinese Journal of Quantum Electronics, 2014, 31(3): 372-378. (in Chinese) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=lzdzxb201403019 [10] Payne M C, Teter M P, Allan D C. Iterative minimization techniques for abinitio total-energy mglculations-molecular-dynamics and conjugate gradients[J]. Rev Mod Phys, 1992, 64: 1045-1097. doi: 10.1103/RevModPhys.64.1045 [11] Rössler U. Energy bands for Csi(greens-function method)[J]. Bull Am Phys Soc, 1969, 14: 331. [12] Zhang F P, Lu Q M, Zhang X, et al. First principle investigation of electronic structure of CaMnO3 thermoelectric compound oxides[J]. J Alloys Compds, 2011, 509(2): 542-545. doi: 10.1016/j.jallcom.2010.09.102 [13] Wang V, Ma D, Jia W. Structural and electronic properties of hexagonal ZnO: A hybrid functional study[J]. Solid State Commun, 2012, 152(22): 2045-2048. doi: 10.1016/j.ssc.2012.08.024 [14] Zhang F P, Zhang X, Lu Q M, et al. Effects of Pr doping on thermoelectric transport properties of Ca3-xPrxCo4O9[J]. Solid State Sci, 2011, 13(7): 1443-1447. doi: 10.1016/j.solidstatesciences.2011.05.009 [15] Nolas G S, Sharp J, Goldsmid H J. Thermoelectrics: Basic Principles and New Materials Developments[M]. Berlin: Springer, 2001. -
下载:
点击查看大图
图(5) / 表(2)
计量
- 文章访问数: 7172
- HTML全文浏览量: 2109
- PDF下载量: 221
