Scanning electron microscopy, atomic force microscopy, and Raman spectroscopy were used to characterize the microstructure of photoluminescent porous silicon (PS) layers formed by the anodic etching (HF:H2O:ethanol), at various current densities, of p-type (100) silicon wafers possessing resitivity in the range 1-2 Ω cm. Existing models for the origin of luminescence in PS are not supported by our observations. Cross-sectional as well as surface atomic force micrographs show the material to be clumpy rather than columnar; rodlike structures are not observed down to a scale of 40 nm. A three-dimensional model of the mesostructure of porous silicon is discussed. Room-temperature Raman scattering measurements show no evidence for a-Si:H or polysilanes and the material reported here is composed of 10 nm roughly spherical Si nanocrytallites rather than 3 nm wires postulated in standard quantum confinement models.

Original Publication Citation

The following article appeared in F. Ruiz, C. Vázquez-López, Jesus González-Hernández, and David D. Allred, G. Romero Paredes and R. Peña-Sierra and G. Torres Delgado, "Mesostructure of photoluminescent porous silicon," Journal of Vacuum Science Technology A 12(4), 2565 71 (1994). and may be found at [http://avspublications.org/jvsta/resource/1/jvtad6/v12/i4/p2565_s1][http://dx.doi.org/1.1116/1.57958].

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Peer-Reviewed Article

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American Vacuum Society




Physical and Mathematical Sciences


Physics and Astronomy