The local structure of porous silicon investigated by EXAFS

✍ Scribed by G. Dalba; P. Fornasini; M. Grazioli; R. Grisenti; Y. Soldo; F. Rocca

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 175 KB
• Volume: 208-209
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)00750-p

✦ Synopsis

X-ray absorption measurements at the K-edge of silicon have been done in transmission mode on three powdered samples of porous silicon (p-Si) with 50%, 65% and 80% porosity, prepared by decreasing the HF content in the anodic solution. The analysis of EXAFS reveals a crystal-like structure of p-Si at least up to the third coordination shell. A slight progressive reduction of coordination numbers and increase of Debye-Waller factors with respect to c-Si is found in passing from the first to the third coordination shell; this behaviour is connected to the limited range of homogeneous structural regions in p-Si. The Debye-Waller factors increase with decreasing porosity, indicating a more ordered local structure in samples prepared with lower HF content and corresponding to the highest porosity.