The effect of substrate doping and the choice of oxidizer on the reactivity of energetic porous silicon-oxidizer composites were examined in this study. Porous silicon samples were prepared from N and P-type substrates with widely different dopant concentrations, and impregnated with perchlorate salts or sulfur to form energetic composites, which were characterized using differential scanning calorimetry. While the low temperature exothermic reactions with perchlorate salts were found to be unaffected by the substrate doping properties, low temperature reactions with sulfur were found to be affected by the substrate doping. This is attributed to the effect of substrate doping on the microstructure of the porous silicon formed. (C) 2014 Elsevier B.V. All rights reserved.