I  U  P  A  C

News & Notices

Organizations & People

Standing Committees




..Macro. Symp.

..Solubility Data



Links of Interest

Search the Site

Home Page


Pure Appl. Chem. Vol. 72, Nos. 1-2, pp. 237-243, 2000

Special Topic Issue on the Theme of
Nanostructured Systems


Optical absorption property of oxidized free-standing porous silicon films

Dongsheng Xu, Guolin Guo*, Linlin Gui, Youqi Tang, and G. G. Qin

*Institute of Physical Chemistry, Peking University, Beijing 10871, P. R.China

Abstract: We have systematically studied the evolution of the optical absorption of free-standing PS films during thermal oxidation at 200°C in air. Our experiment results show the evolution of transmission curve is quite complicated, which red-shifts first and then blue-shifts during thermal oxidation. At the same time, the transmission at the low energy decreases first and then increases. We propose an explanation as follows: (1) the energy gap associated with each crystallite should increase during thermal oxidation process, due to the quantum confinement effect; (2) the energy gap should decrease with an increase in oxygen termination atoms. Both the increasing of the gap due to the quantum confinement effect and the decreasing of the gap due to the Si-O bond formation cause a complicated evolution of optical absorption.

Back to Contents for access to full text

Page last modified 5 May 2000.
Copyright ©2000 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web manager.