掺磷纳米硅薄膜的微结构

采用喇曼(Raman)散射谱、高分辨率电子显微镜(HRTEM)和原子力显微镜(AFM)对掺磷纳米硅薄膜的微结构进行了分析,并对纳米硅薄膜的传导机制进行了探讨.结果表明:掺磷纳米硅薄膜由尺寸为2～4*#nm的晶粒和2～3个原子层厚的非晶界面构成,计算得到薄膜的晶态比为40%～55%.与本征纳米硅薄膜相比,掺磷纳米硅薄膜晶粒尺寸和晶态比没有明显变化,电导率却提高了2个数量级.随着掺磷浓度增加,纳米硅薄膜的晶粒尺寸、晶态比及电导率逐渐增大.AFM观察表明掺磷纳米硅薄膜由尺寸介于15～20*#nm的团簇构成,团簇排列具有带状特征.

Structure Characteristics of Phosphorus-Doped Hydrogenated Nano-Crystalline Silicon Films

By Raman spectroscopy, high-resolution electron microscope and atomic force microscope, the structure of phosphorus-doped hydrogenated nano-crystalline silicon films (nc-Si (P)∶H) was analyzed The films possess orderly arranged cluster feature in the size of 15~20nm. The films are composed of nano-crystalline grain and amorphous silicon, the crystalline volume fraction of the films is 40％~55％, the average grain size is between 2 and 4?nm. The grain size, the crystalline volume fraction and the conductivity of the nc-Si (P)∶H increase as the doping concentration is increased. Compared with undoped hydrogenated nano-crystalline silicon films, the conductivity of nc-Si(P)∶H is increased almost 2 orders. Possible connection between the ordered cluster characteristics and the higher conductivity was finally appointed.