Improvement of the luminescence in p-type as-prepared or dye impregnated porous silicon microcavities

We have realized distributed Bragg reflectors and microcavities with a remarkable optical quality (R-max. = 99.5% at 850 nm, FWHM = 5 nm at 772 nm) with low doped p-type silicon. This is due to a strong decrease of the porous Si/bulk Si interface roughness that was obtained by low-temperature anodization. The properties of porous silicon microcavities are investigated by photoluminescence and reflection measurements. We also have filled porous silicon with Rhodamine 800 dye. The spontaneous emission spectrum of the optically excited Rhodamine 800 is drastically modified by microcavity effect: the peak emission intensity is increased, the line width is narrowed. The results demonstrate that using all porous silicon or dye-filled microcavities provides new possibilities to improve the properties of photonic devices. (C) 1999 Elsevier Science B.V. All rights reserved.