(100)应变对正交相Ca_2P_(0.25)Si_(0.75)能带结构及光学性质的影响  

The Effect of Energy Band Structure and Optical Properties of the Orthorhombic of Ca_2P_(0.25)Si_(0.75)Strained on the(100) Surface

作　　者：岑伟富 杨吟野[1] 范梦慧[1] 姚娟[1] 黄金保[1] 

机构地区：[1]贵州民族大学理学院,贵阳550025

出　　处：《信息记录材料》2014年第3期30-36,共7页Information Recording Materials

基　　金：国家自然科学基金(No.51266002);教育部科学技术研究重点项目(210200);贵州省科学技术联合基金项目(LKM201130);贵州省优秀科技教育人才省长专项资金项目(201174)资助项目

摘　　要：采用第一性原理赝势平面波方法对（100）应变下正交相Ca2P0.25Si0.75的能带结构及光学性质进行模拟计算.计算结果表明：（100）面在晶格发生100％～116％张应变时,带隙随着应变增加而减小;在晶格发生96％～100％压应变时,带隙随着张应变的增加而增加;88％～96％压应变时,带隙随着压应变的增加而减小;当压应变大于88％后转变为间接带半导体.当施加应变后光学性质发生显著的变化：随着压应变的增加静态介电常数、折射率逐渐减小,张应变则反之.施加压应变反射向低能方向偏移,施加张应变反射向高能方向偏移,但施加应变对反射区域的影响不显著.施压应变吸收谱、光电导率的变化与介电函数和折射率相反.综上所述,应变可以改变Ca2P0.25Si0.75的电子结构和光学常数,是调节Ca2P0.25Si0.75光电传输性能的有效手段.Energy band structure and optical properties of the orthorhombic of Ca2P0.25Si0.75 strained on the （100） surface have been calculated by the first-principle pseudo-potential method based on density functional theory （DFT）. The results show that in the tensile strain range of 100%-116% Ca2P0.25Si0.75 is direct semiconductor and the band gap decrease with the increase of strain, in the compressive strain range of 96%-100% it is increase with the increase of strain, while in the compressive strain range of 88%-96% it decreases with the increase of strain, when the compressive strain exceed 88% Ca2P0.25Si0.75 turn to indirect semiconductor. The optical properties changed significantly by strain. The dielectric constant and the refractive index were decreased with increase of compressive strain, while they were increased with increase of tensile strain. The reflectivity moved to low energy direction with increase of compressive strain, while moved to high energy direction with increase of tensile strain, but the influence of strain on the reflection area was not significant. The absorption and the conductivity were increased with increase of compressive strain, while they were decreased with increase of tensile strain. In conclusion, the energy band structure and optical properties of the cubic of Ca2P0.25Si0.75 could be changed by strain, it is effective means for adjusting the photoelectric transmission performance of orthorhombic of Ca2P0.25Si0.75.

关 键 词：应变 能带结构 光学性质 C 第一性原理 

分 类 号：O472.3[理学—半导体物理]