第一性原理的广义梯度近似+U方法的纤锌矿Zn1-xMgxO极化特性与Zn0.75Mg0.25O/ZnO 界面能带偏差研究

吴孔平; 齐剑; 彭波; 汤琨; 叶建东; 朱顺明; 顾书林

doi:10.7498/aps.64.187304

摘要

在纤锌矿结构Zn1-xMgxO/ZnO异质结构中发现了高迁移率的二维电子气(2DEG), 2DEG 的产生很可能是由于界面上存在不连续极化, 而且2DEG通常也被认为是由极化电荷产生的结果. 为了探索2DEG的形成机理及其产生的根源, 研究Zn1-xMgxO合金的极化特性与ZnO/Zn1-xMgxO超晶格的能带排列是非常必要的. 基于第一性原理广义梯度近似+U方法研究了Zn1-xMgxO合金的自发极化随Mg组分x的变化关系, 其中极化特性的计算采用Berry-phase方法. 由于ZnO与Zn1-xMgxO 面内晶格参数大小相当, ZnO 与Zn1-xMgxO 的界面匹配度优良, 所以ZnO/Zn1-xMgxO 超晶格模型较容易建立. 计算了Mg0.25Zn0.75O/ZnO超晶格静电势的面内平均及其沿着Z(0001)方向上的宏观平均. (5+3)Mg0.25Zn0.75O/ZnO超晶格拥有较大的尺寸, 确保远离界面的Mg0.25Zn0.75O与ZnO区域与块体计算情况一致. 除此之外, 基于宏观平均为能量参考, 计算得到Mg0.25Zn0.75O/ZnO超晶格界面处价带偏差为0.26 eV, 并且导带偏差与价带偏差的比值处于合理区间, 这与近来实验上报道的结果相符. 除了ZnO在[0001]方向上产生自发极化外, 由于在ZnO中引入Mg杂质会产生应变应力, 导致MgxZn1-xO层产生额外的极化值. 这样必然会在Mg0.25Zn0.75O/Zn界面处产生非连续极化现象, 促使单极性电荷在界面处积累, 从而在Mg0.25Zn0.75O/Zn超晶格中产生内在电场. 此外, 计算了Mg0.25Zn0.75O/ZnO超晶格的能带排列, 由于价带偏差 EV=0.26 eV与导带偏差EC=0.33 eV, 表明能带遵循I型排列. Mg0.25Zn0.75O/ZnO 的这种能带排列方式足以让电子与空穴在势阱中产生禁闭作用. 2DEG在电子学与光电子学领域都有重要应用, 本文的研究结果将对Mg0.25Zn0.75O/ZnO 界面2DEG的设计与优化中起到重要作用, 并且可以作为研究其他Mg组分的MgxZn1-xO/ZnO超晶格界面电子气特性的参考依据.

关键词:

Abstract

Two-dimensional (2D) electron gas with high-mobility is found in wurtzite ZnO/Zn(Mg)O heterostructure, which probably arises from the polarization discontinuity at the ZnO/Zn(Mg)O interface, and the 2D electron gas in the heterostructure is usually also regarded as resulting from polarization-induced charge. In order to explore both the formation mechanism and the origin of the 2D electron gas in ZnMgO/ZnO heterostructure, it is necessary to study the polarization properties of Zn1-xMgxO alloy and energy band alignment of ZnO/Zn1-xMgxO super-lattice. In this paper, we study the polarization properties of Zn1-xMgxO alloy with different Mg compositions by using first-principles calculations with GGA+U method, and the polarization properties are calculated according to Berry-phase method. Owing to the excellent match between the in-plane lattice constants of ZnO and Zn1-xMgxO, the lattice constants of the ZnO and Zn1-xMgxO interface are similar, ZnO/Zn1-xMgxO super-lattice could be constructed easily. The planar-averaged electrostatic potential for the Mg0.25Zn0.75O/ZnO super-lattice and the macroscopically averaged potential along Z(0001) direction are calculated. The large size of (5+3) Mg0.25Zn0.75O/ZnO super-lattice ensures the convergence of potential to its bulk value in the region of the ZnO layer and Mg0.25Zn0.75O layer far from ZnO/Zn1-xMgxO interface. Besides, the valence band offset at the Mg0.25Zn0.75O/ZnO interface is calculated to be 0.26~eV based on the macroscopically averaged potential mentioned above, and the ratio of conduction band offset (EC) to valence band offset (EV) is in a reasonable range, and this is in substantial agreement with the values reported in recent experimental results. Because strain induces additional piezoelectric polarization in MgxZn1-xO, which is introduced by Mg dopant, the lack of inversion symmetry and the bulk ZnO induce its spontaneous polarization in the [0001] direction. The polarization discontinuity at the Mg0.25Zn0.75O/ZnO interface leads to the charge accumulation in the form of interface monopoles, giving rise to built-in electric fields in the super-lattice. In addition, energy alignment determination of the Mg0.25Zn0.75O/ZnO super-lattice is performed, which shows a type-I band alignment with EV=0.26 eV and EC=0.33 eV. The determination of the band alignment indicates that the Mg0.25Zn0.75O/ZnO super-lattice is competent to the confining of both electron and hole. These findings will be useful for designing and optimizing the 2D electron gas at Mg0.25Zn0.75O/ZnO interface, which can be regarded as an important reference for studying the 2D electron gas at MgxZn1-xO/ZnO super-lattices for electronics and optoelectronics applications.

Keywords:

作者及机构信息

1.
安徽理工大学电气与信息工程学院, 淮南 232001;

2.
南京大学电子科学与工程学院, 微结构国家实验室, 南京 210093

通信作者: 吴孔平, kpwu@aust.edu.cn;slgu@nju.edu.cn ; 顾书林, kpwu@aust.edu.cn;slgu@nju.edu.cn

基金项目: 国家自然科学基金(批准号: 61274058, 61025020, 61322403)、安徽省自然科学基金(批准号: 1208085QF116)和江苏省自然科学基金(批准号: BK2011437, BK20130013)资助的课题.

Authors and contacts

1.
School of Electrical and Information Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, China;

2.
Nanjing National Laboratory of Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China

Corresponding author: Wu Kong-Ping, kpwu@aust.edu.cn;slgu@nju.edu.cn ; Gu Shu-Lin, kpwu@aust.edu.cn;slgu@nju.edu.cn

Funds: Project supported by the National Natural Science Foundation of China (Grant Nos. 61274058, 61025020, 61322403), the Natural Science Foundation of Anhui Province of China (Grant No. 1208085QF116) and the Natural Science Foundation of Jiangsu Province of China (Grant Nos. BK2011437, BK20130013).

参考文献

[1]	Chakhalian J, Millis A J, Rondinelli J 2012 Nat. Mater. 11 92
[2]	Hwang H Y, Iwasa Y, Kawasaki M, Keimer B, Nagaosa N, Tokura Y 2012 Nat. Mater. 11 103
[3]	Ji X, Zhu Y, Chen M M, Su L X, Chen A Q, Gui X C, Xiang R, Tang Z K 2014 Sci. Rep. 4 4185
[4]	Tsukazaki A, Ohtomo A, Kita T, Ohno Y, Ohno H, Kawasaki M 2007 Science 315 1388
[5]	Tsukazaki A, Akasaka S, Nakahara K, Ohno Y, Ohno H, Maryenko D, Ohtomo A, Kawasaki M 2010 Nat. Mater. 9 889
[6]	Han K, Tang N, Ye J D, Duan J X, Liu Y C, Teo K L, Shen B 2012 Appl. Phys. Lett. 100 192105
[7]	Chen H, Gu S L, Liu J G, Ye J D, Tang K, Zhu S M, Zheng Y D 2011 Appl. Phys. Lett. 99 211906
[8]	Ye J D, Lim S T, Bosman M, Gu S L, Zheng Y D, Tan H H, Jagadish C, Sun X W, Teo K L 2012 Sci. Rep. 2 533
[9]	Monroy E, Omnes F, Calle F 2003 Semicond. Sci. Technol. 18 R33
[10]	Fan M M, Liu K W, Chen X, Zhang Z Z, Li B H, Zhao H F, Shen D Z 2015 J. Mater. Chem. C 3 313
[11]	Zhu Y Z, Chen G D, Ye H, Walsh A, Moon C Y, Wei S H 2008 Phys. Rev. B 77 245209
[12]	Wu K P, Jiang J H, Tang K, Gu S L, Ye J D, Zhu S M, Lu K L, Zhou M R, Xu M X, Zhang R, Zheng Y D 2014 J. Magn. Magn. Mater. 355 51
[13]	Zhang W, Xue J S, Zhou X W, Zhang Y, Liu Z Y, Zhang J C, Hao Y 2012 Chin. Phys. B 21 077103
[14]	Liu N Y, Liu L, Wang L, Yang W, Li D, Li L, Cao W Y, Lu C M, Wan C H, Chen W H, Hu X D 2012 Chin. Phys. B 21 017806
[15]	Rao X, Wang R Z, Gao J X, Yan H 2015 Acta Phys. Sin. 64 107303(in Chinese) [饶雪, 王如志, 曹觉先, 严辉 2015 64 107303]
[16]	Niranjan M K, Wang Y, Jaswal S S, Tsymbal E Y 2009 Phys. Rev. Lett. 103 016804
[17]	Wang Y, Niranjan M K, Janicka K, Velev J P, Zhuravlev M Y, Jaswal S S, Tsymbal E Y 2010 Phys. Rev. B 82 094114
[18]	Wei S, Zunger A 1998 Appl. Phys. Lett. 72 2011
[19]	Gruber T, Kirchner C, Kling R, Reuss F, Waag A 2004 Appl. Phys. Lett. 84 5359
[20]	Park S, Ahn D 2005 Appl. Phys. Lett. 87 253509
[21]	Rao G, Sauberlich F, Klein A 2005 Appl. Phys. Lett. 87 032101
[22]	Olson D C, Shaheen S E, White M S, Mitchell W J, van Hest M F A M, Collins R T, Ginley D S 2007 Adv. Funct. Mater. 17 264
[23]	Ohtomo A, Kawasaki M, Ohkubo I, Koinuma H, Yasuda T, Segawa Y 1999 Appl. Phys. Lett. 75 980
[24]	Janotti A, van de Walle C G 2007 Phys. Rev. B 75 121201
[25]	Coli G, Bajaj K 2001 Appl. Phys. Lett. 78 2861
[26]	Su S C, Lu Y M, Zhang Z Z, Shan C X, Li B H, Shen D Z, Yao B, Zhang J Y, Zhao D X, Fan X W 2008 Appl. Phys. Lett. 93 082108
[27]	Wu X, Vanderbilt D, Hamann D R 2005 Phys. Rev. B 72 035105
[28]	Bretagnon T, Lefebvre P, Guillet T, Taliercio T, Gil B, Morhain C 2007 Appl. Phys. Lett. 90 201912
[29]	Morhain C, Bretagnon T, Lefebvre P, Tang X, Valvin P, Guillet T, Gil B, Taliercio T, Teisseire D M, Vinter B, Deparis C 2005 Phys. Rev. B 72 241305
[30]	van de Valle C G, Martin R M 1987 Phys. Rev. B 35 8154
[31]	Ohtomo A, Kawasaki M, Koida T, Masubuchi K, Koinuma H, Sakurai Y, Yoshida Y, Yasuda T, Segawa Y 1998 Appl. Phys. Lett. 72 2466

施引文献

[1]	Chakhalian J, Millis A J, Rondinelli J 2012 Nat. Mater. 11 92
[2]	Hwang H Y, Iwasa Y, Kawasaki M, Keimer B, Nagaosa N, Tokura Y 2012 Nat. Mater. 11 103
[3]	Ji X, Zhu Y, Chen M M, Su L X, Chen A Q, Gui X C, Xiang R, Tang Z K 2014 Sci. Rep. 4 4185
[4]	Tsukazaki A, Ohtomo A, Kita T, Ohno Y, Ohno H, Kawasaki M 2007 Science 315 1388
[5]	Tsukazaki A, Akasaka S, Nakahara K, Ohno Y, Ohno H, Maryenko D, Ohtomo A, Kawasaki M 2010 Nat. Mater. 9 889
[6]	Han K, Tang N, Ye J D, Duan J X, Liu Y C, Teo K L, Shen B 2012 Appl. Phys. Lett. 100 192105
[7]	Chen H, Gu S L, Liu J G, Ye J D, Tang K, Zhu S M, Zheng Y D 2011 Appl. Phys. Lett. 99 211906
[8]	Ye J D, Lim S T, Bosman M, Gu S L, Zheng Y D, Tan H H, Jagadish C, Sun X W, Teo K L 2012 Sci. Rep. 2 533
[9]	Monroy E, Omnes F, Calle F 2003 Semicond. Sci. Technol. 18 R33
[10]	Fan M M, Liu K W, Chen X, Zhang Z Z, Li B H, Zhao H F, Shen D Z 2015 J. Mater. Chem. C 3 313
[11]	Zhu Y Z, Chen G D, Ye H, Walsh A, Moon C Y, Wei S H 2008 Phys. Rev. B 77 245209
[12]	Wu K P, Jiang J H, Tang K, Gu S L, Ye J D, Zhu S M, Lu K L, Zhou M R, Xu M X, Zhang R, Zheng Y D 2014 J. Magn. Magn. Mater. 355 51
[13]	Zhang W, Xue J S, Zhou X W, Zhang Y, Liu Z Y, Zhang J C, Hao Y 2012 Chin. Phys. B 21 077103
[14]	Liu N Y, Liu L, Wang L, Yang W, Li D, Li L, Cao W Y, Lu C M, Wan C H, Chen W H, Hu X D 2012 Chin. Phys. B 21 017806
[15]	Rao X, Wang R Z, Gao J X, Yan H 2015 Acta Phys. Sin. 64 107303(in Chinese) [饶雪, 王如志, 曹觉先, 严辉 2015 64 107303]
[16]	Niranjan M K, Wang Y, Jaswal S S, Tsymbal E Y 2009 Phys. Rev. Lett. 103 016804
[17]	Wang Y, Niranjan M K, Janicka K, Velev J P, Zhuravlev M Y, Jaswal S S, Tsymbal E Y 2010 Phys. Rev. B 82 094114
[18]	Wei S, Zunger A 1998 Appl. Phys. Lett. 72 2011
[19]	Gruber T, Kirchner C, Kling R, Reuss F, Waag A 2004 Appl. Phys. Lett. 84 5359
[20]	Park S, Ahn D 2005 Appl. Phys. Lett. 87 253509
[21]	Rao G, Sauberlich F, Klein A 2005 Appl. Phys. Lett. 87 032101
[22]	Olson D C, Shaheen S E, White M S, Mitchell W J, van Hest M F A M, Collins R T, Ginley D S 2007 Adv. Funct. Mater. 17 264
[23]	Ohtomo A, Kawasaki M, Ohkubo I, Koinuma H, Yasuda T, Segawa Y 1999 Appl. Phys. Lett. 75 980
[24]	Janotti A, van de Walle C G 2007 Phys. Rev. B 75 121201
[25]	Coli G, Bajaj K 2001 Appl. Phys. Lett. 78 2861
[26]	Su S C, Lu Y M, Zhang Z Z, Shan C X, Li B H, Shen D Z, Yao B, Zhang J Y, Zhao D X, Fan X W 2008 Appl. Phys. Lett. 93 082108
[27]	Wu X, Vanderbilt D, Hamann D R 2005 Phys. Rev. B 72 035105
[28]	Bretagnon T, Lefebvre P, Guillet T, Taliercio T, Gil B, Morhain C 2007 Appl. Phys. Lett. 90 201912
[29]	Morhain C, Bretagnon T, Lefebvre P, Tang X, Valvin P, Guillet T, Gil B, Taliercio T, Teisseire D M, Vinter B, Deparis C 2005 Phys. Rev. B 72 241305
[30]	van de Valle C G, Martin R M 1987 Phys. Rev. B 35 8154
[31]	Ohtomo A, Kawasaki M, Koida T, Masubuchi K, Koinuma H, Sakurai Y, Yoshida Y, Yasuda T, Segawa Y 1998 Appl. Phys. Lett. 72 2466

[1]	郑鹏飞, 柳志旭, 王超, 刘卫芳. 基团替代调控无铅有机钙钛矿铁电体的极化和压电特性的第一性原理研究. , 2024, 73(12): 126202. doi: 10.7498/aps.73.20240385
[2]	陈忠, 华林强, 张津, 龚成, 柳晓军. 基于氧化镁晶体中级联四波混频过程的紫外飞秒光脉冲产生. , 2021, 70(6): 064201. doi: 10.7498/aps.70.20201573
[3]	姜伟, 赵欢, 汪国崔, 王新柯, 韩鹏, 孙文峰, 叶佳声, 冯胜飞, 张岩. 应用太赫兹焦平面成像方法研究氧化镁晶体在太赫兹波段的双折射特性. , 2020, 69(20): 208702. doi: 10.7498/aps.69.20200766
[4]	李酽, 张琳彬, 李娇, 连晓雪, 朱俊武. 电场条件下氧化锌结晶特性及极化产物的拉曼光谱分析. , 2019, 68(7): 070701. doi: 10.7498/aps.68.20181961
[5]	李酽, 李娇, 陈丽丽, 连晓雪, 朱俊武. 外电场极化对纳米氧化锌拉曼活性及气敏性能的影响. , 2018, 67(14): 140701. doi: 10.7498/aps.67.20180182
[6]	吴孔平, 孙昌旭, 马文飞, 王杰, 魏巍, 蔡俊, 陈昌兆, 任斌, 桑立雯, 廖梅勇. 铝-金刚石界面电子特性与界面肖特基势垒的杂化密度泛函理论HSE06的研究. , 2017, 66(8): 088102. doi: 10.7498/aps.66.088102
[7]	肖小红, 李世春. SrBi4Ti4O15的化学键性质和铁电性研究. , 2016, 65(6): 063101. doi: 10.7498/aps.65.063101
[8]	范巍, 曾雉. 氧化镁纳米多晶的微结构和磁性. , 2014, 63(4): 047503. doi: 10.7498/aps.63.047503
[9]	牛海波, 陈光德, 伍叶龙, 耶红刚. 空位对纤锌矿型AlN自发极化影响的最大局域化Wannier函数方法研究. , 2014, 63(16): 167701. doi: 10.7498/aps.63.167701
[10]	马明磊, 吴坚, 杨沐, 宁永强, 商广义. 基于两端自发荧光辐射的808nm半导体激光器增益偏振特性实验表征和能带分析. , 2013, 62(17): 174209. doi: 10.7498/aps.62.174209
[11]	陈亮, 徐灿, 张小芳. 氧化镁纳米管团簇电子结构的密度泛函研究. , 2009, 58(3): 1603-1607. doi: 10.7498/aps.58.1603
[12]	孔月婵, 郑有炓, 周春红, 邓永桢, 顾书林, 沈波, 张荣, 韩平, 江若琏, 施毅. AlGaN/GaN异质结构中极化与势垒层掺杂对二维电子气的影响. , 2004, 53(7): 2320-2324. doi: 10.7498/aps.53.2320
[13]	陈三, 谢双媛, 羊亚平, 陈鸿. 双能带三维光子晶体中二能级原子的自发辐射. , 2003, 52(4): 853-858. doi: 10.7498/aps.52.853
[14]	孔月婵, 郑有炓, 储荣明, 顾书林. AlxGa1-xN/GaN异质结构中Al组分对二维电子气性质的影响. , 2003, 52(7): 1756-1760. doi: 10.7498/aps.52.1756
[15]	罗有华, 黄整, 王育竹. 冷原子在静电势阱中的量子力学效应. , 2002, 51(8): 1706-1710. doi: 10.7498/aps.51.1706
[16]	钱祥忠. 液晶SmC相自发极化的统计理论. , 1997, 46(9): 1788-1795. doi: 10.7498/aps.46.1788*
[17]	李富斌. Fr?hlich极化子的能带非抛物性效应理论. , 1991, 40(4): 610-615. doi: 10.7498/aps.40.610
[18]	厉彦民, 赵光安. 双极化子的能带,稳定性与热力学特性. , 1984, 33(2): 273-276. doi: 10.7498/aps.33.273
[19]	蒲富恪, 王鼎盛. 非均匀铁磁体自发磁化的平均场理论. , 1978, 27(4): 439-447. doi: 10.7498/aps.27.439
[20]	李景德. ABO₃型晶体中氧的电子自发极化. , 1966, 22(2): 188-196. doi: 10.7498/aps.22.188

计量

文章访问数: 6364
PDF下载量: 449
被引次数: 0

姓名
邮箱
手机号码
标题
留言内容
验证码

搜索

留言板