Electron Emission Properties of Diamond Nanocones on Freestanding Diamond Films

Large-area diamond conical nanostructure arrays were formed on freestanding diamond films using a hot filament chemical vapor deposition system with negative biasing of the substrates. Results of scanning electron microscopy and transmission electron microscopy studies showed that the energetic methylic ions during the self-organized selective sputtering process dominantly contribute to the formation of diamond cone arrays with controlled morphology based on a neutral-ion charge exchange collision model. Field emission properties, measured by a home-made double probe scanning electron microscopy, presented lower threshold voltage and higher emission current density compared with those of planar diamond films. This study has opened the possibility of using diamond cone arrays as display device and point electron source with excellent electron emission ability