Structural and electrical defects in amorphous silicon probed by positrons and electrons
Structural and electrical defects in amorphous silicon probed by positrons and electrons
复制标题
用正电子和电子探测非晶硅的结构和电缺陷
DOI：
10.1063/1.351993
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发表时间：
1992
影响因子：
3.2
通讯作者：
F. Saris
中科院分区：
文献类型：
--
作者：
S. Roorda;R. Hakvoort;A. Veen;P. Stolk;F. Saris
用可变能量正电子湮没谱（PAS）和光生自由载流子寿命测量研究了离子注入制备的纯非晶硅的结构。一般来说，PAS测量被认为对空位型缺陷敏感，而载流子寿命取决于带隙态的密度（例如，悬挂键）。PAS测量表明，通过在500 °C下进行热退火，可以降低正电子俘获缺陷的密度。与结构缺陷的去除同时，带隙态的密度降低，如由增加的光生载流子寿命的10倍所指示的。一些材料已经被注入H+并在低温（150 °C）下退火。预计氢钝化与应变和悬挂键相关的电缺陷，并且实际上在该材料中增加了光生载流子寿命。此外，PAS测量无法将这种材料与500 °C退火的非晶材料区分开来。
The structure of pure amorphous Si, prepared by ion implantation, has been investigated by variable‐energy positron annihilation spectroscopy (PAS) and lifetime measurements of optically generated free carriers. In general, PAS measurements are thought to be sensitive to vacancy‐type defects while the carrier lifetime depends on the density of band‐gap states (e.g., dangling bonds). The PAS measurements indicate that the density of positron‐trapping defects can be reduced by thermal annealing at 500 °C. Concurrent with the removal of structural defects the density of band gap states is reduced as indicated by an increased photocarrier lifetime by a factor of 10. Some material has been implanted with H+ and annealed at a low temperature (150 °C). The hydrogen is expected to passivate electrical defects associated with strained and dangling bonds and indeed the photocarrier lifetime is increased in this material. Moreover, the PAS measurements cannot distinguish this material from 500 °C annealed amorphous ...