Photoluminescence from porous silicon impregnated with cobalt phthalocyanine

Photoluminescence quenching of porous silicon in presence of various analytes is used for sensing purposes. Sensor elements based on unmodified porous silicon exhibit high sensitivity in gas phase detection but relatively low operational stability. Stabilization of porous silicon surface with organic molecules enables to enhance operational stability and optimize sensor response for specific analytes. We modified porous silicon surface using cobalt phthalocyanine by means of physical adsorption in the porous matrix. We observed modified photoluminescence quenching response from these porous silicon samples impregnated with cobalt phthalocyanine. From concentration dependence of photoluminescence quenching in presence of linear alcohols in gas phase we determined sensitivity of sensor response, from long-term evolution of porous silicon photoluminescence intensity we evaluated operational stability of sensor elements. Link between chemical properties of phthalocyanine molecules and variation of sensor response of impregnated porous silicon is discussed.