沉积时间对非晶碳/Mo2C混合薄膜场发射性能的影响

Impact of Deposition Time on Field Emission Characters of Compound Film of Amorphous Carbon and Mo2C

在Al2O3衬底上采用微波等离子体增强化学气相沉积（MPCVD）系统中沉积薄膜,反应气体为CH4、H2。从样品的Raman谱中可以分析出薄膜中含有非晶碳成分。XRD有明显的晶态Mo2C衍射峰,所制备的薄膜为非晶碳/Mo2C混合膜。在高真空室中测量了样品的场发射特性,其开启场强为0.55 V/μm,在1.8 V/μm电场下测得样品的场发射电流密度为6.8 mA/cm^2。CCD图中可以看到样品有比较好的发光特性。研究了在一定反应条件下,沉积时间对样品场发射特性的影响,4 h制备的样品场发射性能最好。良好的场发射性能决定了所制备的样品是一种好的场致发射体。

The film was deposited on A1203 substrate in microwave plasma chemical vapor deposition system with The reactive gases of CH4 and H2. The microstructure and ingredient were studied by using Raman spectrum and X - ray diffraction （XRD） .Field emission characteristics was measured in high vacuum chamber. Its turn- on. electric field was 0.55v/μm. The film contains amorphous carbon and Mo2 C. We studied th impaction of reaction time on its field emission characteristics. The right time was 4 hours. It could be a good kind of field electron emitter.