Hewa-Kasakarage Nishshanka N, Kirsanova Maria, Nemchinov Alexander, Schmall Nickolas, El-Khoury Patrick Z, Tarnovsky Alexander N, Zamkov Mikhail
Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, USA.
J Am Chem Soc. 2009 Jan 28;131(3):1328-34. doi: 10.1021/ja8082895.
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.
我们报道了发光（ZnSe/CdS）/CdS半导体异质结构纳米棒（异质纳米棒）的有机金属合成方法，该方法能使载流子沿结构的主轴实现有效空间分离（II型载流子定位）。纳米棒采用种子生长法制备，通过在纤锌矿型ZnSe/CdS核壳纳米晶体的[000±1]晶面上使20 - 100 nm的CdS外延生长成核。CdS在两个方向上生长速率的差异确保了ZnSe/CdS种子在最终结构中的位置偏离异质纳米棒的中心，从而导致载流子波函数沿异质结构呈空间不对称分布。目前的工作展示了（ZnSe/CdS）/CdS异质纳米棒的许多独特性质，包括增强的量子限制斯塔克效应幅度以及吸收能量的亚纳秒级切换，这些性质在电吸收开关和超灵敏电荷探测器中具有实际应用价值。
