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为了研究较厚的多孔硅层结构及氧化分布对电子发射特性的影响,采用恒流和脉冲腐蚀制备了单层和多层结构的多孔硅,并对这两种结构的多孔硅分别进行定场强和变场强电化学氧化。根据扫描电子显微镜和X射线能谱仪对多孔硅结构和氧含量分布的测量结果,以及对电子发射特性和所提出的多孔硅电子源模型的比较和分析,结果发现:孔隙率交替变化的多层多孔硅结构可以优化电场分布,变场强的电化学氧化使氧含量分布均匀,电子在发射时可以得到持续加速和收敛。单层结构的多孔硅经过定场强电化学氧化后,氧含量分布上层高而下层低,电子不能得到持续加速且具有散射的特点。变场强氧化的多层多孔硅电子发射特性优于定场强氧化的单层多孔硅电子源。
In order to study the effect of thicker porous silicon layer structure and oxidation distribution on the electron emission characteristics, single-layer and multi-layer porous silicon were prepared by constant current and pulse erosion, and the porous silicon of these two structures were respectively subjected to field Strong and variable field strong electrochemical oxidation. According to the measurement results of the porous silicon structure and the oxygen content distribution by the scanning electron microscope and the X-ray energy dispersive spectrometer, as well as the comparison and analysis of the electron emission characteristics and the proposed porous silicon electron source model, it is found that: The porous silicon structure can optimize the electric field distribution. The electrochemical oxidation with varying field strength can make the oxygen content evenly distributed and the electrons can be accelerated and converged continuously during the emission. After the monolayer porous silicon is subjected to field strong electrochemical oxidation, the oxygen content distribution is high in the upper layer and low in the lower layer, and the electrons can not be continuously accelerated and have the characteristics of scattering. The field emission enhanced oxidation multilayer porous silicon electron emission characteristics better than the field strong oxidation of single-layer porous silicon electron source.