掺铝3C-SiC电子结构的第一性原理计算及其微波介电性能  

First principles calculation of electronic structure for Al-doped 3C-SiC and its microwave dielectric properties

作　　者：李智敏[1,2] 施建章[1] 卫晓黑[1] 李培咸[1] 黄云霞[1] 李桂芳[1] 郝跃[2] 

机构地区：[1]西安电子科技大学技术物理学院,西安710071 [2]西安电子科技大学宽禁带半导体材料与器件重点实验室,西安710071

出　　处：《物理学报》2012年第23期410-415,共6页Acta Physica Sinica

基　　金：中央高校基本科研业务费专项资金资助项目(批准号:K5051205006;K5051105006)资助的课题~~

摘　　要：采用基于密度泛函理论的第一性原理平面波超软赝势法,对比研究了未掺杂和Al掺杂3C-SiC材料的电子结构和介电常数.结果表明:Al掺杂后,Fermi能级进入价带,带隙宽度略为加宽,在8.2—12.4 GHz范围内介电常数大幅度增大.利用燃烧合成法制备了Al掺杂的3C-SiC粉体吸收剂,通过矢量网络分析仪测试了样品在8.2—12.4 GHz范围内的微波介电常数,验证了理论计算结果,并讨论了微波损耗机理.The electronic structure and permittivity of Al-doped 3C-SiC are studied by using the first principles plane-wave pseudopotential method based on the density functional theory, and compared with those of undoped 3C-SiC. Results show that the Fermi energy level introduced into valence band and band gap is slightly widened through AI doping for 3C-SiC, and that the permittivity is greatly improved in a frequency range of 8.2-12.4 GHz. A1 doped 3C-SiC powder absorber is prepared by combustion synthesis, and the permittivities of the samples are measured in the frequency range of 8.2-12.4 GHz by vector network analyzer, which validates the results of theoretical calculation. The mechanism of microwave loss is discussed.

关 键 词：Al掺杂SiC 第一性原理 能带结构 介电性能 

分 类 号：O469[理学—凝聚态物理]