单晶纳米硅薄膜的制备及其场发射特性

用小电流、特殊配比溶液的电化学阳极腐蚀法在p型、〈100〉晶向、0.01Ω·cm电阻率的硅片制备了大面积纳米硅薄膜.通过SEM,TEM,XRD和Raman光谱技术分析薄膜颗粒的微细结构.实验结果表明该纳米硅薄膜由直径为10～20nm,晶向一致的颗粒紧密排列而成,具有很好的物理化学稳定性.系统研究了薄膜结构特征和溶液配比、腐蚀时间、腐蚀电流密度的关系.成功观察到该薄膜具有很好的场发射特性,在0.1μA/cm2电流密度下,其开启电场为3V/μm,接近碳纳米管的1.1V/μm.

Fabrication and Field Emission of Silicon Nano-Crystalline Film

The silicon nano-crystalline (nc-Si) film is fabricated on 〈100〉 orientation,0.01Ω*cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si are examined by the scanning electron microscopy,transmission electron microscopy,and X-ray diffraction spectroscopy,respectively.The average size of particle is estimated by Raman spectroscopy.The results show that the particle size of nc-Si film is scattered from 10nm to 20nm,the alignment is compact,the orientation is uniform,the expansion of lattice constant is negligible,and mechanical robustness and stability are good.The correlations between film structure and the experiment parameters such as etching time,HF concentration,and etching current density are discussed.As a potential application,efficient field emission is observed from the nc-Si film,and the turn-on field is about 3V/μm at 0.1μA/cm2 of current density,which is close to carbon nanotube film's.