| Porous silicon can be used in the area of silicon-based photo-electronics deviceswith great prosperity, but it is still far away from real implement so far. Among thosepractical problems, the most important one is to solve the instability of luminance ofporous silicon.In this paper, we have discussed the effects on luminance stability throughdifferent treatments to porous silicon. We adopted anodic etching to make poroussilicon samples under different experimental conditions, after that, we treated thosesamples through cathodic reduction and acid treatment respectively in order toimprove the samples' surface. With PL measurement we analyzed those conditions'effects on luminance of porous silicon. By means of atom force microscope (AFM)we discussed the samples' surface look and components.Experimental results indicate that acid treatment is a useful treatment toimprove luminance efficiency, and cathodic reduction, from another aspect, canenhance sample's luminance stability, compared with the samples without cathodicreduction. We also use PL measurement to samples that have been stored for oneyear, and pay attention to the two peaks in the PL graph with different excitationwavelength. We find that the effects of gradual oxidization exposed in the air isgreater on untreated samples than those samples treated by cathodic reduction, andthe effects on longer wave peak is greater than shorter one. Moreover, the intensityof short peak will increase with the decline of excitation wavelength. To thosesamples exposed in the air, when aging reach to a certain level, the peak andintensity will not change under the excitation wavelength of 250 nm. Consideringour experimental results we discussed the phgtoluminescence mechanism of poroussilicon.
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