Thickness and strain engineering of structural and electronic properties for 2D square-octagon AlN  

作　　者：Wantong Hou Zhanbin Qi Hang Zang Yan Yan Zhiming Shi 

机构地区：[1]College of Science,Changchun University,Changchun,China [2]State Key Laboratory of Luminescence and Applications,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun,China

出　　处：《International Journal of Smart and Nano Materials》2020年第3期288-297,共10页国际智能和纳米材料杂志（英文）

基　　金：This work was supported by the National Natural Science Foundation of China[61804152,61834008].

摘　　要：Two-dimensional(2D)semiconductors exhibit great potential to minimize the size and drastically reduce the energy consumption of optoelectronic devices due to promising features induced by quantum confinement.It has achieved many successes in infra-red and visible light optoelectronic devices.The study on ultra-wide band gap 2D semiconductors except h-BN are still limited,however,the requirement is more and more urgent.Inspired by the progresses of III-nitride semiconductors in recent several decades,2D AlN is highly expected to be a new member of ultra-wide band gap 2D semiconductors.In this work,we employed the first-principles calculations to investigate the structural and electronic properties of 2D AlN.We revealed that few-layer AlN acquires a square-octagon(so-AlN)configuration in the vertical direction when the number of atomic layers n is smaller than 16.With increasing the thickness from 2 ML to 8 ML,the band gap decreased due to the weakening of quantum confinement effect.We demonstrated the intrinsic indirect band gap can be tuned to be direct by applying different direction strains for so-AlN.Our results open new avenues for their application in nano-optoelectronics.

关 键 词：Square-octagon AlN electronic structures strain engineering ultra-wide band gap semiconductors firstprinciples calculation 

分 类 号：TB3[一般工业技术—材料科学与工程]