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.
Hewa-Kasakarage, Nishshanka N.; Kirsanova, Maria; Nemchinov, Alexander; Schmall, Nickolas; El-Khoury, Patrick Z.; Tarnovsky, Alexander N.; and Zamkov, Mikhail, "Radiative Recombination Of Spatially Extended Excitons In (znse/cds)/cds Heterostructured Nanorods" (2009). Chemistry Faculty Publications. 55.
Journal Of The American Chemical Society