掺杂纳米硅薄膜中电子自旋共振研究

研究了掺杂纳米硅薄膜(nc∶Si∶H)中的电子自旋共振(ESR)及与之相关的缺陷态.样品是用等离子体增强化学气相沉积方法制成,为两相结构,即纳米晶粒镶嵌于非晶本体之中.对掺磷的nc-Si∶H样品,测量出其ESR信号的g值为1.9990—1.9991,线宽ΔH_pp为(40—42)×10^-4T,ESR密度Nss为10¹⁷cm^-3数量级.对掺硼的nc-Si∶H样品,其ESR信号的g值为2.0076—2.0078,ΔH_{关键词： 纳米硅薄膜 微结构 电子自旋共振}

INVESTIGATIONS INTO ELECTRON SPIN RESONANCE IN DOPED NANOCRYSTALLINE SILICON FILMS

We report here the studies of electron spin resonance (ESR) and its related defect states in doped nanocrystalline silicon films (nc-Si: H).The samples used,which was prepared by plasma enhanced CVD method,are of two phases in structure,i.e.,nanocrystallites embedded in the amorphous matrix.For phosphorus doped nc-Si:H samples,the measured ESR g-values are 1.9990—1.9991,the line width △Hpp(40—42) × 10-4 T,and the ESR density Nss is of order of 1017 cm-3.For boron doped nc-Si: H samples,the measured ESR g-values are 2.0076—2.0078,△Hpp is about 18×10-4 T,and Nss is of order of 1016 cm-3.Considering the micro-structural and conducting characteristics of these kinds of films,we discuss and give explanations to the ESR sources,their △Hpp and Nss as well.We ascribe the ESR signals in phosphorus doped nc-Si:H to the unpaired electrons in the high density defect states located in the interfaces of nanocrys tallites/amorphous matrix,and that in boron doped ones to the unpaired electrons in the valence band-tail states in the a Si:H tissue of their amorphous matrix.