title: Radiative recombination of spatially extended excitons in (ZnSe/CdS)/CdS heterostructured nanorods.
abstract: We report on organometallic synthesis of luminescent (ZnSe/CdS)/CdS semiconductor heterostructured nanorods (hetero-NRs) that produce an efficient spatial separation of carriers along the main axis of the structure (type II carrier localization). Nanorods were fabricated using a seeded-type approach by nucleating the growth of 20-100 nm CdS extensions at [000 +/- 1] facets of wurtzite ZnSe/CdS core/shell nanocrystals. The difference in growth rates of CdS in each of the two directions ensures that the position of ZnSe/CdS seeds in the final structure is offset from the center of hetero-NRs, resulting in a spatially asymmetric distribution of carrier wave functions along the heterostructure. Present work demonstrates a number of unique properties of (ZnSe/CdS)/CdS hetero-NRs, including enhanced magnitude of quantum confined Stark effect and subnanosecond switching of absorption energies that can find practical applications in electroabsorption switches and ultrasensitive charge detectors.
authors.affiliation: Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, USA.
authors.forename: Nishshanka N
authors.initials: NN
authors.lastname: Hewa-Kasakarage
authors.forename: Maria
authors.initials: M
authors.lastname: Kirsanova
authors.forename: Alexander
authors.initials: A
authors.lastname: Nemchinov
authors.forename: Nickolas
authors.initials: N
authors.lastname: Schmall
authors.forename: Patrick Z
authors.initials: PZ
authors.lastname: El-Khoury
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Tarnovsky
authors.forename: Mikhail
authors.initials: M
authors.lastname: Zamkov