Highly stable carbon nanotube and graphene field emitters for miniature X-ray tubes = 초소형 X-선 튜브를 위한 고안정성 탄소나노튜브 및 그래핀 전계방출원

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 324
  • Download : 0
Carbon nanotube (CNT) field emitters that exhibit extremely high stability against high-voltage arcing has been demonstrated. The CNT emitters were fabricated on a sharp copper tip substrate that produces a high electric field. A metal mixture composed of silver and copper nanoparticles was used as a binder to attach CNTs to the substrate. Due to the strong adhesion of the metal mixture, CNTs were not detached from the substrate even after many intense arcing events. Through electrical conditioning of the as-prepared CNT emitters, vertically-standing CNTs with almost the same heights were formed on the substrate surface and most of loosely-bound impurities were removed from the substrate. Consequently, no arcing was observed during the normal operation of the CNT emitters and the emission current kept constant even after intentionally induced arcing. Additionally, a simple and convenient route was presented to fabricate freestanding graphene nanosheets and large-area/patterned graphene nanofilms by thermal annealing of indium (In) and graphite mixture. In particles mixed with graphite powder catalytically oxidize the graphite powder and produce carbon oxide gases. The carbon oxide gases are then catalytically graphitized to form graphene nanostructures on In. The morphologies of the graphene nanostructures can be controlled by the In geometry: vertically-standing graphene nanosheets are synthesized using In particles and a graphene nanofilm is grown on a thin In layer. In is then completely removed, and thus high-purity graphene is finally produced. The graphene nanosheets exhibited excellent field-emission performance due to high-density edges. In addition, the graphene nanofilms show electrical conductivities comparable to or better than that of reduced graphene oxide. Furthermore, a large-area or a patterned graphene nanofilm is synthesized using a uniform or a pre-patterned In layer, respectively.
Advisors
Cho, Sung Ohresearcher조성오researcher
Description
한국과학기술원 :원자력및양자공학과,
Publisher
한국과학기술원
Issue Date
2017
Identifier
325007
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 원자력및양자공학과, 2017.2,[viii, 114 p. :]

Keywords

Carbon Nanotube; Graphene; Field emission; Vacuum breakdown; High stability; Metal binder; Electrical Conditioning; Miniature X-ray tube; Liquid metal catalyst; 탄소나노튜브; 그래핀; 전계방출; 방전; 고안정성; 금속접착제; 전기적 후처리; 초소형 X-선 튜브; 액체 금속 촉매

URI
http://hdl.handle.net/10203/241957
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=675786&flag=dissertation
Appears in Collection
NE-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0