Carbon nanotubes(CNTs)were grown into anodic aluminum oxide(AAO)channels by chemical vapor deposition(CVD)using C2H2/N2mixtures as feeding gas,which can be used as field emitters.The bottom surface of AAO template was...Carbon nanotubes(CNTs)were grown into anodic aluminum oxide(AAO)channels by chemical vapor deposition(CVD)using C2H2/N2mixtures as feeding gas,which can be used as field emitters.The bottom surface of AAO template was etched slightly and the tips of CNTs were explored as the field emission arrays which were uniform and vertical.Field emission characterization showed a low turn-on field about 3.25 V/m and high emission current about 30 mA/cm2with the electric field about 4 V/m.These superior field emission characteristics could be attributed to low density of vertical CNTs and higher conductivity of the substrate.展开更多
Laser was coupled into an optical fiber,on which covered a layer of well-aligned carbon nanotubes(CNTs)serving as cathode,to tune the field emission of the cathode.CNT arrays as field emission cathode were synthesized...Laser was coupled into an optical fiber,on which covered a layer of well-aligned carbon nanotubes(CNTs)serving as cathode,to tune the field emission of the cathode.CNT arrays as field emission cathode were synthesized by chemical vapor deposition(CVD)on a naked fiber core.When the laser was coupled into the fiber,the turn-on voltage(Vto at a current density of 1 mA cm?2)decreased from 1.0 to 0.9 kV and the emission current density increased from 0.83 mA cm?2(at a 1 kV bias voltage)to3.04 mA cm?2 on 40μm diameter fiber.A photon absorption mechanism is attributed to the field emission improvement.The estimated effective work function of CNT arrays on the optical fiber decrease from 4.89 to 4.29 eV.The results show the possibility of constructing a waveguide type laser modulated field emission cathode.展开更多
基金supported by China National Funds for Distinguished Young Scientists(Grant No.61125101)the Science and Technology on Vacuum&Cryogenics Technology and Physics Laboratory
文摘Carbon nanotubes(CNTs)were grown into anodic aluminum oxide(AAO)channels by chemical vapor deposition(CVD)using C2H2/N2mixtures as feeding gas,which can be used as field emitters.The bottom surface of AAO template was etched slightly and the tips of CNTs were explored as the field emission arrays which were uniform and vertical.Field emission characterization showed a low turn-on field about 3.25 V/m and high emission current about 30 mA/cm2with the electric field about 4 V/m.These superior field emission characteristics could be attributed to low density of vertical CNTs and higher conductivity of the substrate.
基金supported by the National Natural Science Foundation of China(Grant Nos.91123018,61172041,61172040,50975226,and 60801022)the National Hi-Tech Research and Development Program of China("863"Project)(Grant No.2008AA03A314)the Fundamental Research Funds for the Central Universities
文摘Laser was coupled into an optical fiber,on which covered a layer of well-aligned carbon nanotubes(CNTs)serving as cathode,to tune the field emission of the cathode.CNT arrays as field emission cathode were synthesized by chemical vapor deposition(CVD)on a naked fiber core.When the laser was coupled into the fiber,the turn-on voltage(Vto at a current density of 1 mA cm?2)decreased from 1.0 to 0.9 kV and the emission current density increased from 0.83 mA cm?2(at a 1 kV bias voltage)to3.04 mA cm?2 on 40μm diameter fiber.A photon absorption mechanism is attributed to the field emission improvement.The estimated effective work function of CNT arrays on the optical fiber decrease from 4.89 to 4.29 eV.The results show the possibility of constructing a waveguide type laser modulated field emission cathode.
