title: Time-resolved photoluminescence characteristics of subnanometer ZnO clusters confined in the micropores of zeolites.
abstract: Subnanometric ZnO clusters confined in different micropore zeolites are studied by steady-state and nanosecond time-resolved photoluminescence (PL) spectroscopy. The microsecond-scale lifetime is observed at room temperature for ZnO clusters confined in zeolites, which is significantly different from that of macrocrystalline ZnO on the external surface of zeolites. The dependence of luminescence lifetime on the amount of ZnO in zeolites indicates that the electron-phonon interactions between the ZnO clusters and the zeolite host significantly affect the dynamic relaxation process of ZnO clusters. The long lifetime luminescence of ZnO clusters can be achieved by weakening the coupling of electronic transition to zeolites host phonons. The similar long-lived luminescence is obtained when dispersing ZnO clusters into the porous SiO2. It is suggested that encapsulating the semiconductor cluster in the porous support is a possible way to inhibit or to retard the electron-hole recombination.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Shi
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Zhaochi
authors.initials: Z
authors.lastname: Feng
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.forename: Pinliang
authors.initials: P
authors.lastname: Ying
authors.forename: Can
authors.initials: C
authors.lastname: Li