Enhanced field emission from metal-coated carbon nanowalls

Kaneko, Yoshiki; Terada, Kazuhiro; Teii, Kungen

doi:10.7567/1347-4065/ab43cd

Cited by 5 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The other techniques are hybridization of CNWs and other nanomaterials. These include decoration of CNWs with metal nanoparticles, , formation of CNW/nanocrystalline diamond composite films, − formation of CNW/CNT hybrid films, and coating of CNWs on Si microspikes . Diamond possesses a number of outstanding properties such as high hardness, high thermal conductivity, and high carrier mobility and can maintain negative electron affinity stably even in ambient air .…”

Section: Introductionmentioning

confidence: 99%

Enhanced Field Emission from Ultrananocrystalline Diamond-Decorated Carbon Nanowalls Prepared by a Self-Assembly Seeding Technique

Huang

Harajiri

Wang

et al. 2022

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Vertically aligned nanographite structures, the so-called carbon nanowalls (CNWs), are decorated with ultrananocrystalline diamond particles by an electrostatic self-assembly seeding technique, followed by short-term growth in plasma chemical vapor deposition, to enhance field emission efficiency and stability. A nanodiamond suspension diluted with a dispersion medium with high wettability on CNWs enables seeding of diamond nanograins consisting of nanoparticles of 3–5 nm in diameter on CNWs with high uniformity and minimal aggregation and control of their number density. The field emission turn-on field depends upon the density of diamond nanograins and decreases from 3.0 V μm–1 for bare CNWs to 1.8 V μm–1 for diamond-decorated CNWs together with about an order of magnitude increase in current density. Finite element modeling indicates that only a part of decorating diamond located at the top of nanowalls actually contributes to field amplification and emission. The diamond-decorated CNWs show also higher emission stability with much larger time constants of current degradation than the bare CNWs for long-term duration. The enhanced emission efficiency is explained by larger field amplification rather than lowering of the tunneling barrier, while the enhanced emission stability is attributed to the higher robustness of diamond.

show abstract

Section: Introductionmentioning

confidence: 99%

Enhanced Field Emission from Ultrananocrystalline Diamond-Decorated Carbon Nanowalls Prepared by a Self-Assembly Seeding Technique

Huang

Harajiri

Wang

et al. 2022

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…One is chemical/physical modification of CNWs such as surface nitridation for increasing sp 2 domain size, crystallinity, and conductivity [15] and increasing graphitization for a transition from semiconducting to semi-metallic conduction [12]. The other is combination of CNWs with other nanomaterials such as decoration of CNWs with metal nanoparticles [16,17] and carbon nanotubes [18], formation of CNWs/nanocrytalline diamond composite films [19][20][21][22][23], and coating of CNWs on Si microspikes [24]. Diamond is potentially superior to metals for the purpose of materials combination as it has high hardness, high thermal conductivity, high chemical inertness, and even negative electron affinity.…”

Section: Introductionmentioning

confidence: 99%

Control of electrostatic self-assembly seeding of diamond nanoparticles on carbon nanowalls

Huang¹,

Wu²,

Hijiya³

et al. 2021

Nanotechnology

Self Cite

View full text Add to dashboard Cite

Seeding of diamond nanoparticles on vertically-aligned multi-layer graphene, the so-called carbon nanowalls (CNWs), is studied by using deionized water, ethylene glycol, ethanol, and formamide as dispersion mediums. Detonation nanodiamond particles show the smallest mean size and size distribution with a high positive zeta potential when dispersed in ethanol. The contact angle of ethanol on CNWs is almost zero degree, confirming highly wetting behaviour. The diamond nanoparticles dispersed in ethanol are distributed the most uniformly with minimal aggregation on CNWs as opposed to those dispersed in other liquids. The resulting diamond nanoparticle-seeded CNWs, followed by short-term growth in microwave plasma chemical vapor deposition, show a marked decrease in field emission turn-on field down to 1.3 V μm−1 together with a large increase in current density, compared to bare CNWs without diamond seeding. The results provide a way to control the density, size, and uniformity (spacing) of diamond nanoparticles on CNWs and should be applied to fabricate hybrid materials and devices using nanodiamond and nanocarbons.

show abstract

“…19 Similarly, a metal contact to the surface of CNWs is an important issue because metal nanoparticle deposition on CNWs could increase emission performance. 20,21 Even for gas sensor applications, a contact between CNWs and the front/back metal electrode is important for measuring current variation upon gas sensing with high sensitivity and accuracy. [12][13][14][15] The metal contact behavior on CNWs may be different from that on graphene owing to the crystalline domains with amorphous phase.…”

mentioning

confidence: 99%

Electrical Characteristics of Metal Contacts to Carbon Nanowalls

Sun

Cho

Huang

et al. 2022

ECS J. Solid State Sci. Technol.

Self Cite

View full text Add to dashboard Cite

The electrical characteristics of metal contacts to vertically-aligned nanographite structures, the so-called carbon nanowalls (CNWs), are examined using nickel as the electrode material. The total resistance between a pair of electrodes on CNWs is regarded as the sum of the serial resistance of CNWs and two metal-CNWs contacts to measure the contact resistance and specific contact resistivity by the transmission line method and transfer line method, respectively. The contact resistance and resistivity are around 2.8 Ω and 0.1 Ω cm2, respectively, at room temperature and decrease gently to 2.4 Ω and 0.06 Ω cm2, respectively, when the temperature is increased up to 300 °C. The apparent activation energy corresponding to the conduction barrier at the contact is in the range of 10−3 eV to 10−2 eV, which is comparable with that for the sheet resistance of CNWs. The contact resistance occupies a large portion of the total resistance between a pair of electrodes even at high temperatures, thus affecting electrical signal measurement in electronic and electrochemical device applications.

show abstract

Enhanced field emission from metal-coated carbon nanowalls

Cited by 5 publications

References 27 publications

Enhanced Field Emission from Ultrananocrystalline Diamond-Decorated Carbon Nanowalls Prepared by a Self-Assembly Seeding Technique

Enhanced Field Emission from Ultrananocrystalline Diamond-Decorated Carbon Nanowalls Prepared by a Self-Assembly Seeding Technique

Control of electrostatic self-assembly seeding of diamond nanoparticles on carbon nanowalls

Electrical Characteristics of Metal Contacts to Carbon Nanowalls

Contact Info

Product

Resources

About