COUPLING EFFECT OF SURFACE VIBRATION AND QUANTUM CONFINEMENT CARRIERSIN POROUS SILICON

This paper deals with the structural characterization and the optical proper ties of deuterium terminated porous silicon (D-PS) fabricated b y electrochemical anodization with DF-ethanol-D6 isotope electrolyte, Both the deuterium terminated and the usual hydrogen terminated porous silicons (W-PS) were characterized with transmission electron microsc ope analysis and Fourier transform infrared spectroscopy. These charac terizations show that the nanometer crystalline structure of D-PS is a lmost the same as that of H-PS except for the surface termination. Alt hough both PS show the same valence band energy shift, which was confi rmed by X-ray photoemission spectroscopy, the photoluminescence spectr um of D-PS was different from that of H-PS. These results indicate tha t the surface vibration of terminated atoms couples to the excited ene rgy states of quantum-confined carriers, which induces the surface-tra pped states of Si nanocrystals.