石墨烯含量对碳纳米管电极发射器结构和运行稳定性的影响  

Field Emission Properties of Discrete Emitter Made of Graphene and Carbon Nanotubes

作　　者：张冬冬 李明[2] ZHANG Dongdong;LI Ming(Medical Equipment Department,Hengshui People’s Hospital,Hengshui 053000,China;College of Materials Science and Engineering,North China Electric Power University,Baoding 071000,China)

机构地区：[1]衡水市人民医院医学装备处,衡水053000 [2]华北电力大学材料科学与工程学院,保定071000

出　　处：《真空科学与技术学报》2021年第3期291-295,共5页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目(50775157)。

摘　　要：利用石墨烯电学特性与碳纳米管场发射特性,加入不同含量的石墨烯浆料并对比了各试样场发射特性与器件运行稳定性。实验测试研究结果表明:石墨烯对碳纳米管实现了良好的分隔作用,形成了更大的碳纳米管间隙,降低了电场屏蔽的程度。碳纳米管周围被石墨烯紧密填充,起到了良好的固定作用,能够使碳纳米管获得多级场发射效应。随着石墨烯加入量由2%提高到6%时,由石墨烯与碳纳米管组成的复合阴极也表现出了更强的场发射能力。6%的试样表现出最优的性能,提高电场强度后,获得了更快增大的电流密度。石墨烯含量为2%、4%、6%的三种试样表现出了良好的阴极稳定性,石墨烯含量为6%时达到该阈值电流密度所需的电场最低。A discrete field emitter was fabricated by gluing carbon nanotubes(CNTs) onto tip-apex of pencil-lead with graphene slurry.The influence of the graphene-content on the field emission properties of the self-developed emitter was investigated.The preliminary results show that the graphene significantly improved the field emission property of the lab-made.Specifically, the de-bundled CNTs, being well dispersed, enclosed and tightly fixed to the tip-apex by graphene, formed the independent multiple emission sites.As the graphene content increased, the emission current density and field enhancement factor changed in an increase-decrease mode, the emission onset field decreased.The threshold current density from the emitter with a graphene content of 6 wt%,in the graphene aqueous slurry, was reached at the lowest electric field.In addition, the field emission behavior of the self-developed field emitters, with different graphene-contents, was found to be fairly stable.

关 键 词：石墨烯 碳纳米管 结构 运行稳定性 

分 类 号：TG146[一般工业技术—材料科学与工程]