Cd对纤锌矿ZnO极化特性的影响以及Zn_(0.75)Cd_(0.25)O/ZnO界面能带偏差的第一性原理研究  

First-principle Study on Effect of Cd on Polarization of Wurtzite Structure ZnO and Band Offset at Zn_(0.75)Cd_(0.25)O/ZnO Interfaces

作　　者：吴孔平[1] 慈能达 汤琨[2] 叶建东[2] 朱顺明[2] 顾书林[2] 

机构地区：[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

出　　处：《人工晶体学报》2015年第9期2577-2582,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(61025020;61274058);安徽省自然科学基金(1208085QF116)

摘　　要：基于第一性原理GGA+U方法研究了Zn1-xCdxO合金的晶格常数以及自发极化随Cd组分x的变化关系,其中极化特性的计算采用Berry-phase方法,同时计算了禁带宽度随Cd组分x的变化关系,并得到了能隙弯曲参数0.69。此外,通过计算宏观平均静电势的方法得到了(5+3)Cd0.25Cd0.75O/Zn O超晶格界面处的价带偏差为0.13 e V,导带偏差与价带偏差的比值为4/13,并且Zn1-xCdxO/Zn O界面两侧能带呈现I型排列,这些研究结果将对Zn1-x CdxO/Zn O界面二维电子气的设计与优化起到重要作用。The lattice parameter and spontaneous polarization properties of Zn1-xCdxO alloy at different Cd compositions were studied using first-principles calculations with GGA ＋ U method,and the polarization properties were calculated according to Berry-phase method. At the same time,energy band-gap of Zn1-x CdxO alloy at different Cd compositions was calculated,and the band-gap bowing parameter of 0. 69 was obtained. In addition,the valence band offset at the Zn O / Cd0. 25Zn0. 75 O interface was calculated to be 0.13 e V by the way of electrostatic macroscopic average,and the ratio of conduction band offset（ ΔEC） to valence band offset（ ΔEV） is 4 /13,and the lineup of energy band at the two sides of Zn O/Cd0. 25Zn0. 75 O super-lattice interface shows type-I lineup. These findings will play important role in the design and optimization of two-dimensional electron gas at Zn1-xCdxO / Zn O super-lattices.

关 键 词：自发极化 静电势平均 能带偏差 锌镉氧合金 

分 类 号：O469[理学—凝聚态物理]