Si-29 high resolution solid state nuclear magnetic resonance spectroscopy of porous silicon

Porous silicon has been characterized by Si-29 nuclear magnetic resonance spectroscopy under conditions of static samples, magic angle spinning, decoupling and cross polarization. In a free induction decay experiment, two Si-29 resonances at -80 and -111 ppm were obtained. Cross polarization resulted in a single resonance at -97 ppm. Magic angle spinning and decoupling slightly reduce the linewidth of the Si-29 cross polarized signal, The minor narrowing effect and thr relaxation behavior in the laboratory and rotating frame indicate a homogeneous contribution to the linewidth. The relaxation data suggest that the resonance observed under cross polarization conditions arises from SiH or SiH2 structural elements.