A powdered semiconductor (ZnO) and a polycrystalline sample of perovskite-type LaAIO3 doped with 1% Cr(III) have been subjected to the recently developed technique of diffuse reflectance flash photolysis. In both cases transient absorption spectra are obtained from these powdered, nontransparent samples and these are reported here. Thus, the method allows the direct observation of absorption by transient species formed following pulsed irradiation within powdered samples as well as from highly scattering interfaces demonstrating that the technique has high potential for investigating heterogeneous photochemical systems.
