Fabrication and optical characterization of full color stop band based on rugate-structured porous silicon

The reflection band characteristics of rugate porous silicon (PS) and the effect of an etching time for the formation of rugate photonic structure were investigated. The reflection band of rugate PS shifted to shorter wavelength by about 30 nm as the etching time increased. The effect of frequency for the formation of rugate PS was investigated. The reflection band characteristics of 17 rugate PS samples according to the frequency change were investigated. All parameters but etching frequency were fixed. The values of Ai, B, and t were 11.55 and 63.05 mA and 1000 s. respectively. The frequencies, k(i), varied from 0.22 to 0.38 Hz. and the effect of a frequency for the reflection band characteristics of rugate PS were investigated. Rugate PS exhibited a linear dependence between the reflection wavelengths and the etching frequencies. (C) 2011 Elsevier B.V. All rights reserved.