摘要
本文研究了发可见光的多孔硅薄膜及其粉末的电子顺磁共振(EPR)信号。采用不同电阻率和不同晶向的硅单晶衬底,经过不同条件的阳极氧化制成多孔硅薄膜,其光致发光峰在可见光范围,其EPR信号(标记为PK6)来自三角轴对称的自旋中心,对称轴方向是衬底晶格的〈111〉晶向。该结果说明多孔硅中保留着单晶硅成份。分析PK6的对称性及其g张量主值发现它很可能是硅悬键。多孔硅粉末的EPR信号表现为PK6信号的无规取向平均谱。
Visibly photoluminescentporous Si films and pcwders have been studied by electron paramagnetic
resonance(EPR).In the porous Si films fabricated by anodic etching on crystalline
Si substrates of different resistivities and orientatioas under different anodization conditions,
an EPR signal denoted PK6 has been found to come from trigonally symmetric spin centers
whose axial directions are along the <111>directions of the substrate crystal. This means
that there remains the crystal part in the porous Si. Analysing the symmetry and the g-tensor
of PK6, we find it to be most probably the Si dangling bond. In the porous Si powders, an
isotropic EPR signal is found to come from the PK6 centers with random orientations.
基金
国家自然科学基金
关键词
多孔硅
顺磁共振
发光
Electron paramagnetic resonance
Films
Paramagnetic resonance
Photoluminescence
Porous materials
