Abstract Porous silicon samples were prepared for optical studies by using the photoluminescence (PL), Raman scattering (RS), as well as the absolute reflectance and ellipsometry methods. Results show that the porous Si has low optic constants, and can trap the visible photons of more than 95%, but give no evidence of a strong interband transition existing in the vis-ible region. The Bruggeman effective-medium-approximation (EMA) and Lorentz oscillator models were used in data analyses. Calculations show that the layer dispersion effect may result in a red shift of the PL peak. The possible mechanism for the PL and Raman enhance-ment as well as the photon trap phenomenon was discussed, and was attributed mainly to the random multiple micro-reflections in the porous-Si layer having extremely large internal micro-Burfaces.
Fund: Project supported by the State Education Commission, the State Science and Technology Commission, and the National Natural Science Foundation of China.
Cite this article:
CHEN LIANG-YAO, HOU XIAO-YUAN, HUANG DA-MING, ZHANG FU-LONG, FENG XING-WEI, YANG MIN, SU YI, QIAN YOU-HUA, WANG XUN STUDY OF PHOTON-TRAPPING PHENOMENON IN POROUS SILICON LAYER 1994 Acta Phys. Sin. (Overseas Edition) 3 595