摘要
GaN被称为第三代半导体,有着重要的应用前景.本文对其衍生的一维锯齿型纳米管进行了系统研究,重点研究了ⅢA-ⅦA主族的所有非金属原子低浓度掺杂纳米管后的化学结合特性、电子结构、输运特性及栅极电压调控效应等,并且有一些重要的发现,如:掺杂纳米管具有良好的能量与热稳定性,它们的结合能、形成能及杂质原子周围化学键的平均键长与掺杂原子的原子序数(原子半径)有密切联系;杂质原子与纳米管之间的电荷转移与它们之间的相对电负性有直接关系.更重要的是,研究发现虽然本征纳米管是半导体,但非金属原子掺杂后,纳米管的电子相具有明显的奇-偶效应,即掺杂第ⅢA,ⅤA,ⅦA族原子后,纳米管仍为半导体,而掺杂第ⅣA,ⅥA族原子后,纳米管变为金属,这些现象与孤对电子态有密切关系.对半导体材料的载流子迁移率研究发现:掺杂异质原子,能调控纳米管的空穴及电子迁移率产生1个数量级的差异,特别是较高的栅极电压能明显提高空穴及电子迁移率,如当栅极电压为18 V时,空穴迁移率相对未加电压时的情况增大了近20倍.
GaN is known as the third generation of semiconductor and holds promising applications.In this present work,one-dimensional zigzag nanotubes derived from GaN are studied in depth,mainly focusing on their chemical bondings,electronic structures,transport properties,and the regulating effects under gate voltage for nanotubes doped with low-concentration non-metallic atoms in main-groups ⅢA-ⅦA.Some important findings are obtained,such as the chemical bonds around a heteroatom atom,and their average bond length,binding energy,and chemical formation energy are closely related to the atomic number(the atomic radius),and the charge transfer between heteroatom and nanotubes is directly related to their relative electronegativity.More importantly,we find that although the intrinsic nanotube is a semiconductor,when it is doped with nonmetallic atoms,the electronic phase of nanotube possesses an obvious odd-even effect.Namely,after being doped by hetero-atoms in main-groups ⅢA,ⅤA,ⅦA,nanotubes are semiconductors,but they becomes metals after having been doped with hetero-atoms in main-groups ⅣA and ⅥA.This phenomenon has a close relation with the lone-paired electronic state.And also,It is found that with atom doping,the difference between carriers’ mobilities(the hole mobility and electron mobility) of semiconducting tubes can be regulated to reach one order of magnitude,especially the hole mobility and electron mobility can be obviously enhanced by a higher gate voltage.For example,when the gate voltage is increased to 18 V,the hole mobility rises nearly 20 times compared with the case without gate voltage.
作者
汤家鑫
范志强
邓小清
张振华
Tang Jia-Xin;Fan Zhi-Qiang;Deng Xiao-Qing;Zhang Zhen-Hua(Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering,Changsha University of Science and Technology,Changsha 410114,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第11期293-304,共12页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61771076,12074046)
湖南省自然科学基金(批准号:2020JJ4625,2021JJ30733)
湖南省教育厅科研项目(批准号:19A029)资助的课题.