摘要
石墨烯与金属间过高的接触电阻严重影响了其在微纳电子领域的应用,B掺杂可以有效降低石墨烯的接触电阻。利用第一性原理研究了不同浓度B掺杂对石墨烯吸附多层Au原子的影响。首先计算了不同浓度B掺杂石墨烯的结合能,验证了掺杂石墨烯的稳定性;然后对掺杂石墨烯进行了结构优化并在其表面置入多层Au原子,计算了吸附模型的吸附能、赝能隙、局部态密度、电荷密度分布和电荷转移量。B掺杂浓度分别为1.39%,4.17%,6.94%,9.72%,12.50%和15.28%。结果表明:随着B掺杂浓度的提高,石墨烯吸附多层Au原子体系的赝能隙变宽,吸附能增加,结构稳定性得到提升;B原子与Au原子间杂化作用明显,具有较高的电荷密度和电荷转移量,可有效地降低石墨烯与多层Au原子间的接触电阻;但掺杂浓度为15.28%时,由于浓度过高吸附模型中石墨烯几何结构变形过大。
The high contact resistance between graphene and metal retards the application of graphene in micro-and nano-electronics.Boron(B)doping can effectively reduce the contact resistance of graphene.The influence of dopant concentration on the adsorption of multilayer gold(Au)atoms on B-doped graphene was studied using the first principles theory.Firstly,the binding energy of B-doped graphene with various B concentrations was calculated,and the stability of each B-doped graphene was verified.Then,after structural optimization of B-doped graphene,multilayer Au atoms were introduced into graphene and the adsorption energy,pseudogap,local density of state,charge density distribution,and charge transfer of the adsorption system were analyzed.The B concentrations considered were respectively 1.39%,4.17%,6.94%,9.72%,12.50%and 15.28%.The results show that as B concentration increases,the pseudogap of the adsorption system becomes wider and the adsorption energy rises,leading to a more stable adsorption system.Also,an obvious hybridization between B and Au atoms takes place.This elevates the charge density and promotes the charge transfer at the interface of graphene and Au,which can help reduce the contact resistance between them.However,when the concentration reaches 15.28%,the geometric deformation of graphene becomes intolerable due to a high doping concentration.
作者
卢子龙
安立宝
刘扬
LU Zi-long;AN Li-bao;LIU Yang(College of Mechanical Engineering,North China University ofScience and Technology,Tangshan 063210,Hebei,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2019年第4期64-70,共7页
Journal of Materials Engineering
基金
国家自然科学基金(51472074)
河北省百人计划资助项目(E2012100005)
华北理工大学研究生创新项目(2018522)
