应变ZnO光学和电学特性的第一性原理计算  

First-Principles Calculations of Electrical and Optical Properties of Strained ZnO

作　　者：乔丽萍[1,2] 柴常春[1] 于新海[1] 杨银堂[1] 刘阳[1] 

机构地区：[1]西安电子科技大学微电子学院宽禁带半导体材料与器件重点实验室,西安710071 [2]西藏民族学院信息工程学院,陕西咸阳712082

出　　处：《硅酸盐学报》2015年第4期424-430,共7页Journal of The Chinese Ceramic Society

基　　金：国家重点基础研究发展计划(973计划)项目(2014CC339900);国家自然科学基金(60776034;61162025)项目

摘　　要：基于应变张量理论,建立未应变ZnO与不同Mg组分表征的应变ZnO/Zn_1-xMg_xO超胞模型,进而采用密度泛函理论框架的第一性原理平面波规范-守恒赝势方法,研究应变ZnO的电学和光学特性。计算结果表明,导带电子有效质量随应力增加而稍有增加;'重空穴'带和'轻空穴带'的空穴有效质量几乎未受到应力的影响,而场致分裂带空穴有效质量随应力增加而明显减小,该结果与KP法计算结果一致。光学特性研究表明,在23⁴0 eV高能段,由于应变ZnO的反射率和吸收值均小于未应变ZnO的反射率和吸收值,表明应变ZnO在高能段平均光透射率增加。The supercell modules of unstrained and strained ZnO were established based on the theories of strain tensor,in which the magnitude of stress was determined by Mg content of Zn_(1-x)Mg_xO substrate.The electrical and optical properties of strained ZnO were investigated using first-principles calculations of plane wave norm-conserving pseudo-potential technology based on the density functional theory.The calculated results reveal that there is little change in the effective masses of light hole band(LHB) and heavy hole band(HHB) under strain,and the strain leads to a decrease in the effective masses of crystal splitting band(CSB),which are consistent with the calculated results by the KP method.Moreover,the reflectivity and absorptivity of strained ZnO are smaller than those of unstrained ZnO in the high energy range of 23-40 eV,indicating that the average optical transmittance in visible range increases.

关 键 词：氧化锌 第一性原理 应变 分裂能 有效质量 反射率 

分 类 号：O482[理学—固体物理]