METASTABLE-DEFECT GENERATION IN HYDROGENATED AMORPHOUS-SILICON

Article

关键词: A-SI-H;    LIGHT SOAKING;    RECOMBINATION;    PHOTOCONDUCTIVITY;    TEMPERATURE;    KINETICS;    MODEL;   

DOI  :  10.1103/PhysRevB.50.1551

来源: SCIE

【 摘 要 】

We report on the effects of intense light soaking at room temperature (RT) and at 77 K on the defect density in hydrogenated amorphous silicon (a-Si:H). It is found that at short light-soaking times, light soaking at RT is more efficient in creating metastable defects than at 77 K. With increasing light-soaking time, however, 77-K light soaking causes the defect density to increase at a higher rate than does RT light soaking. There are signs that the saturated value of the defect density for 77-K light soaking is larger than that for RT light soaking. Qualitatively, a correlation exists between the increase in the defect density and the decrease in the photoconductivity; however, an inverse proportionality is not observed between the photoconductivity and defect density. For a given defect density, the photoconductivity is smaller for 77-K light soaking than for RT light soaking. The defects generated by 77-K light soaking are found to be stable at 77 K. However, significant annealing of defects occurs after raising the sample temperature to RT. Light-induced annealing of defects is also observed. We explain our results by adopting the views that there is a broad distribution of defect-annealing activation energies and that the defects with small annealing activation energies are more effective recombination centers than those with large annealing activation energies. We show that many other related experimental results can also be accounted for by the above views.

【 授权许可】

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