Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Spatially resolved Raman-measurements at electroluminescent porous n-silicon

: Kozlowski, F.; Lang, W.


Journal of applied physics 72 (1992), Nr.11
ISSN: 0021-8979
ISSN: 1089-7550
Fraunhofer IFT; 2000 dem IZM eingegliedert
Elektrolumineszenz; Modell; oxidation; poröses Silizium; Ramanspektroskopie; Strukturuntersuchung

We have investigated the cross-section of electroluminescent (EL) porous silicon layers (LEPOS) made from n and p doped silicon by means of micro Raman and photoluminescence (PL) spectroscopy to find the luminescence active zone in LEPOS. Special care has been taken to avoid the heating of the sample. Additionally an EDS (Energy Dispersive Spectroscopy)-Scan over the sample cross section has been performed for n-LEPOS to detect the distribution of oxygen. As our n-samples have displayed much better EL properties than our p-samples we have concentrated our investigations on the n-samples. For n-LEPOS, we have found a layered structure with SIOsubKappa/Si at the top followed by a PL-active layer. There are two types of samples showing different forms of Ramanspectra. Type I spectra are narrow and shifted by small values as compared with the Raman-spectra of bulk silicon. They have a shoulder at about 510cmhighminus1 only in the PL-active layer. Type II spectra are broad and shifted by ab out 7 - 10cmhighminus1. All our electroluminescent samples show Raman-spectra of type I.