Observations on the surface and bulk luminescence of porous silicon

Journal Article · Mon Nov 15 04:00:00 EST 1993 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.355156· OSTI ID:6080713

Jiang, D T; Coulthard, I; Sham, T K; Lorimer, J W ^[1]; Frigo, S P ^[2]; Feng, X H ^[3]; Rosenberg, R A ^[4]

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1. Department of Chemistry, University of Western Ontario, London N6A 5B7 (Canada)
2. Synchrotron Radiation Center, University of Wisconsin-Madison, Stoughton, Wisconsin 53589 (United States)
3. Canadian Synchrotron Radiation Facility, Synchrotron Radiation Center, University of Wisconsin-Madison, Stoughton, Wisconsin 53589 (United States)
4. Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Using the x-ray excited optical luminescence technique, we have investigated the soft x-ray induced photoluminescence of porous silicon in the optical region (200--900 nm) and the Si [ital K]-edge x-ray absorption fine structures of porous silicon in the near edge region. It is found that while porous silicon prepared at low current density (20 mA/cm[sup 2] for 20 min) exhibits a single broad luminescence band, porous silicon prepared at high current density (200 mA/cm[sup 2] for 20 min) exhibits three optical luminescence channels; i.e., in addition to the broad peak characteristic of all porous silicon, there are at least two additional optical luminescence channels at shorter wavelengths, one with modest intensity at [similar to]460 nm and the other a weak and very broad peak at [similar to]350 nm. These optical channels have been used to monitor the Si [ital K]-edge absorption of porous silicon in the near edge structure region. Analysis of the data shows that while the band at [similar to]627.5 nm corresponds to the bulk emission, the other channels are of a surface origin. These observations and their implications are discussed.

• OSTI ID: 6080713
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 74:10; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
CURRENT DENSITY
ELECTROMAGNETIC RADIATION
ELEMENTS
ETCHING
LUMINESCENCE
MATERIALS
POROUS MATERIALS
RADIATIONS
SEMIMETALS
SILICON
SURFACE FINISHING
SURFACE PROPERTIES
ULTRAVIOLET RADIATION
VISIBLE RADIATION