Electron–hole reduced effective mass in monoatomic …–O–Ti–O–Ti–O–… quantum wires embedded in the siliceous crystalline matrix of ETS-10

Abstract

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 SiO 2 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 μ of electrons and holes in a one-dimensional quantum sized …–O–Ti–O–Ti–O–… wire having unprecedented geometrical definition (1.66 m e< μ<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 field of optoelectronic and non-linear optics, dominated up to now by quantum confinement in III–V and II–VI semiconductors.