摘要
二维GaN是一种性能优良的半导体光电材料,用途广泛。因此,基于密度泛函理论采用广义梯度近似方法系统研究单层、双层和三层二维GaN的电子结构和光学性质,并与三维GaN体材料进行比较。结果表明:随着维数的降低,二维GaN的能带变宽,各能级的能量值起伏变大;不同于三维GaN,二维GaN量子尺寸效应明显,N的2s态和2p态相互作用增强,出现能带重叠,呈现较好的导电特性;分析费米能级发现导带底附近存在明显表面态,这是因为Ga的4s电子态的贡献;随着二维GaN层数的增加,对紫外光的反射特性越来越好,在特定的能量范围内,二维GaN的能量损失为零。由此可知,研究二维GaN的电子结构和光学性质有助于二维GaN在纳米光电器件中的应用。
Two-dimensional GaN is a type outstanding semiconductor with important applications in photoelectric field. Based on density functional theory using the generalized gradient approximation method, the electronic and optical properties of single, double and three layers two-dimensional GaN have been investigated, which is compared with three-dimensional GaN. The results show that with the reduction of dimensionality, the energy band structure of the two-dimensional GaN has been changed greatly, the energy band has been widened, and the value of each energy level has been fluctuated. Different from the three-dimensional GaN, the quantum size effect of two-dimensional GaN is obvious, for the reason that the interaction between the N 2s and 2p state is enhanced and the overlap of band appears, leading to good conductivity. Analyzing the Fermi energy level, there exists obvious surface state near the bottom, which is mainly contributed by Ga 4s state. With the increase of the number of layers for two-dimensional GaN, the metallic reflection characteristics for ultraviolet light are getting better. In the specific energy range, the energy loss of two-dimensional GaN becomes zero. These results are helpful for applications of two-dimensional GaN in nanometer photoelectric devices.
作者
张陆
任达华
谭兴毅
钱楷
ZHANG Lu;REN Da-hua;TAN Xing-yi;QIAN Kai(School of Information Engineering, Hubei University for Nationalities, Enshi 445000, China)
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2018年第12期2624-2631,共8页
Journal of Synthetic Crystals
基金
国家自然科学金(11864011)
湖北省自然科学基金(2018CFB390)
关键词
二维GaN
第一性原理
电子结构
光学性能
two-dimensional GaN
first-principle
electronic structure
optical property
