Temperature dependence of the photoluminescence of all-porous-silicon optical microcavities

Photoluminescence measurements in all-porous-silicon optical microcavities (PSM) are reported over a wide temperature range. Both continuous wave and time resolved measurements have been performed. The microcavity is formed b y an all porous silicon Fabry-Perot filter made by two distributed Bragg re flectors separated by a lambda-thick PS cavity layer. The luminescence prop erties of PSM are changed with respect to those of PS: a temperature indepe ndent narrowing in the emission line shape, a different temperature depende nce of the emission intensity, and a fractional shortening of the luminesce nce decay time over the 50-300 K temperature interval are achieved. The PSM luminescence properties are explained by the spatial redistribution of the spontaneous emission, by an effective refractive index probed by the photo n mode confined in the cavity layer and by the coupling between the singlet exciton state and the photon mode confined in the cavity layer. The satura tion of the absorption of the distributed Bragg reflector is also addressed . (C) 1999 American Institute of Physics. [S0021-8979(99)04503-X].