AlGaN/GaN纳米异质结构中的二维电子气密度研究  

Two-Dimensional Electron Gas Density Studies in AlGaN/GaN Nanoheterostructures

作　　者：杨帆 许并社[1,2,3] 董海亮 张爱琴[1] 梁建 贾志刚[1,2] YANG Fan;XU Bingshe;DONG Hailiang;ZHANG Aiqin;LIANG Jian;JIA Zhigang(Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;Institute of Advanced Materials and Chemical Engineering,Shanxi-Zheda,Taiyuan 030000,China;Institute of Atomic and Molecular Science,Shaanxi University of Science and Technology,Xi’an 710021,China)

机构地区：[1]太原理工大学新材料界面科学与工程教育部重点实验室,太原030024 [2]山西浙大新材料与化工研究院,太原030000 [3]陕西科技大学材料原子·分子科学研究所,西安710021

出　　处：《人工晶体学报》2023年第6期1136-1144,共9页Journal of Synthetic Crystals

基　　金：国家自然科学基金(21972103,61904120,61604104,51672185);山西浙大新材料与化工研究院研发项目(2021SX-AT001,2021SX-AT002)。

摘　　要：本文设计了纳米线核壳AlGaN/GaN异质结构,研究了势垒层厚度、Al组分、掺杂浓度对平面和纳米线异质结构中二维电子气(2DEG)浓度的影响规律。结果表明,随着势垒层厚度的逐渐增大,两种结构中2DEG浓度增速逐渐减缓,当达到40 nm后,由于表面态电子完全发射,2DEG浓度逐渐稳定不变。随着Al组分的增加,极化效应逐渐增强,使得两种结构在异质界面处的2DEG浓度都逐渐增加。当掺杂浓度逐渐提高时,两者在异质界面处电势差增大,势阱加深,束缚电子能力加强,最终导致2DEG浓度逐渐增加,当掺杂浓度增加到2.0×10^(18)cm^(-3)后,2DEG面密度达到最大值。与平面结构相比,纳米线结构可以实现更高的Al组分,在高Al组分之下,2DEG面密度最高可达5.13×10^(13)cm^(-2),相比于平面结构有较大的提高。In this paper,nanowire core-shell AlGaN/GaN heterostructures were designed and the effects of potential barrier layer thickness,Al component,and doping concentration on the concentration of two-dimensional electron gas(2DEG)in the planar as well as nanowire heterostructures were studied.The results show that,the rise rate of 2DEG concentration in both structures slow down as the thickness of potential barrier layer increases,and when the thickness reaches 40 nm,the 2DEG concentration gradually stabilizes due to the complete emission of surface state electrons.With the increase of Al component,the polarization effect is gradually enhanced,which makes the 2DEG concentration at the heterogeneous interface of both structures gradually increase.When the doping concentration gradually increases,it can be found that potential difference at the heterogeneous interface increases,the potential well deepening and the ability strengthening for bound electron,which finally lead to the gradual increase of 2DEG concentration.The 2DEG surface density reaches its maximum value as the doping concentration increases to 2.0×10^(18)cm^(-3).Compared with the planar structure,the nanowire structure can achieve a higher Al component,and the 2DEG surface density can reach up to 5.13×10^(13)cm^(-2)under the high Al component,which is a large improvement.

关 键 词：ALGAN/GAN 纳米线结构 平面结构 二维电子气浓度 异质结构 能带结构 

分 类 号：O471[理学—半导体物理] O472[理学—物理]