Manipulation of spontaneous emission dynamics of organic dyes in the porous silicon matrix.

The control of the spontaneous emission (SE) rate of dye molecules (4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) and Coumarin 523 (C523)) embedded in the Porous Silicon (PS) matrix has been studied using picosecond resolved fluorescence decay and polarization studies. We have shown that the SE rates of the two organic dyes embedded in the PS matrix depend on the relative positions of the emission maxima of the dyes with respect to electronic band gap energy of the PS matrix. We have also explored that the electronic band gap of the host PS matrix can easily be tuned by partial oxidation of the PS and the nature of SE of the embedded dyes can be tuned accordingly. The demonstrated retardation or enhancement of the spontaneous photon emission may enable the application of fluorescent organic molecules in PS matrix in several quantum optical devices including the realization of single photon sources.