ELECTRON-HOLE REDUCED EFFECTIVE MASS IN MONOATOMIC ...-O-TI-O-TI-O- ... QUANTUM WIRES EMBEDDED IN THE SILICEOUS CRYSTALLINE MATRIX OF ETS-10

Optical absorption edge measurements on a new microporous crystalline material, Engelhard titanosilicate (ETS-10), containing monoatomic ...-O-Ti-O-Ti-O-... wires embedded in an insulating SiO2 guest allowed us to determine the bandgap blue shift due to the charge carrier confinement. This has enabled the determination of the effective reduced mass mu of electrons and holes in a one-dimensional quantum sized ...-O-Ti-O-Ti-O-... wire having unprecedented geometrical definition (1.66 m(e) < mu < 1.97 m(e)). Besides this relevant finding, related to the peculiar structure of ETS-10, the present work underlines the future possible role that micro- and mesoporous materials could play in the held of optoelectronic and non-linear optics, dominated up to now by quantum confinement in III-V and II-VI semiconductors.