Enhanced Electron Field Emission Of Copper Implanted Microcrystalline Diamond Films After Annealing

Ion implantation is an effective surface modification technology for improving conductivity of doped diamond film,can obviously improve the diamond film performance of field emission cold cathode materials.This experiment adopts the ion implantation technology and different annealing process,that the 100 kev,1×1017 ions/cm2 doses of Cu ions were implanted into microcrystalline diamond?MCD?films,which made by microwave plasma chemical vapor deposition?MPCVD?,annealing at different temperatures to explore the best treatment technology enhancing the field emission properties of diamond films.The synthesis of Cu nanoparticles?NPs?and nanographite phase improved the electrical properties of MCD substrate.Cu NPs or nanographite can be used as a “conductive island”,namely carrier and channel of transmission electron,realizing electronic conduction through the electron transition or tunneling?Tunnel Effect?between “conducting island”.In this experiment,field emission scanning electron microscopy?FESEM?,atomic force microscope?AFM?and grazing incidence X-ray diffraction?GXRD?,laser Raman spectroscopy?Raman?and X-ray photoelectron spectrometer?XPS?measurements for sample microstructure accurate characterization,and field emission and electrical properties of samples were measured by the Hall effect?Hall?,high vacuum electron field emission?EFE?measurement.This subject studied the important factors for field emission property and microstructure of MCD films: 1)certain energy and dose of Cu ion implantation;2)annealing treatment methods and different annealing temperature.The main research contents and results are as follows:?1?The samples of Cu ion implantation were placed in N₂ atmosphere at 500 ?,700 ?,900 ? for 1h common thermal annealing?CAT?treatment,respectively,the system studied the influence of Cu ion implantation and annealing for microstructure and EFE performance of MCD films.The results show that Cu ion implantation lead to part sp3 C-C fracture,forming the sp2 C=C and other hanging keys.The presence of Cu nanoparticles at grain boundary and catalytic graphitic phase on its surface formed conduction channels for efficient electron transport,ensuing better EFE properties for Cu ion implanted/annealed MCD film in N₂ atmosphere at 500? with turn-on field at?E0=14.684 V/?m?and EFE current density of 18.642 ?A/cm2 at an applied field of 24.546 V/?m.?2?The samples of Cu ion implantation were placed in N₂ atmosphere at 500?,600?,700?,800? for 1 h rapid thermal annealing?RTA?treatment,respectively,the system studied the influence of Cu ion implantation and annealing for microstructure and EFE performance of MCD films.Compared with CTA,the RTA treatment of the sample overall performance is better.After rapid annealing at 700?,Cu NPs grew up and gathered to grain boundary,which catalytically converted the a-C/disorder graphite into nanographite phase.Samples of turn on field?E0=1.587 V/?m?decreased obviously,and the current density up to 27.571 ?A/cm2 under the electric field of 3.342 V/?m.