The Phenomena of Amplification in 2D Photonic Macroporous Silicon

Effects of increase in absorption of electromagnetic radiation,
amplification of photoconductivity and Raman scattering by 2D structures of
macroporous silicon were investigated. Maximal photoconductivity was measured
(1) at normal incidence of electromagnetic radiation, (2) at a critical angle
concerning macropore walls and (3) at a grazing angle concerning a surface of
structure. Angular dependences of photoconductivity, as well as enhancement of
the photoconductivity in comparison with monocrystal silicon, primary absorption
р-component of electromagnetic radiation testified to formation of surface
electromagnetic waves in illuminated macrporous silicon structures. Its effects
result in amplification of a local electric field on a surface of macroporous silicon
structure and a macropore surface. Electric components of an electromagnetic field
on macropore surface are transferred in volume to distance about le. Shift of a
spectrum maximum in the long-wavelength party is observed at the maximal
amplification of photoconductivity. The measured built-in electric field on a
macropore surface achieves 106 V/cm, the signal of photoconductivity amplifies 102
times, and Raman scattering - up to one order of value.