X-RAY-ABSORPTION AND PHOTOELECTRON SPECTROSCOPIC OBSERVATION OF INTRAZEOLITIC SILICON NANOCLUSTERS

The Si-K near-edge absorption spectra and X-ray photoelectron spectra of silicon nanoclusters encapsulated in the pores of zeolite Y are mea sured; the intrazeolitic Si clusters display a blue shift of the K-edg e (0.5 eV) relative to that of bulk Si and a strong room-temperature p hotoluminescence, which is consistent with the quantum confinement eff ect; the number of Si in the as-prepared sample is estimated to be 20 atoms per unit cell of zeolite Y from both XPS and Si K NEXAFS analysi s.