In situ infrared spectroscopic study of luminescent porous silicon

✍ Scribed by V.M. Dubin; F. Ozanam; J.-N. Chazalviel

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 658 KB
• Volume: 8
• Category: Article
• ISSN: 0924-2031
• DOI: 10.1016/0924-2031(94)00035-f

✦ Synopsis

Porous silicon has been studied using in situ infrared spectroscopy combined with photoluminescence, electroluminescence, photomodulated and electromodulated infrared absorption, when the porous layer is either chemically etched in HF or anodically oxidized. Infrared vibrational spectra indicate that the luminescence is not very sensitive to the chemical state of the surface (hydrogenated or oxidized). A more important point seems to be wetting of the surface. The well-known intense orange-red luminescence is only observed on dry surfaces. Wet surfaces exhibit instead a weak yellow-green luminescence. The photomodulated and electromodulated infrared absorption spectra show that the red luminescence on dry surfaces is associated with a localization of the photocarriers, suggesting that the localization process may be related to the dielectric constant of the embedding medium.