Coupled and decoupled dual quantum systems in one semiconductor nanocrystal

by Battaglia, David Mark; Blackman, Bridgette Renee; Peng, Xiaogang

Dual quantum systems, 0-dimensional quantum dot, and 2-dimensional quantum wells were constructed in one H-VI semiconductor nanocrystal by the epitaxial growth of a barrier (ZnS) layer between the systems in solution. By alteration of the thickness of the barrier layer, the two quantum systems were controlled to either electronically coupled or decoupled. Evidence of optical coupling between the two band gap emissions was also observed. The position and relative intensity of the two emissions can be independently tuned by reaction conditions. Total photoluminescence quantum efficiency of the dual emitting bands reached as high as 30% at room temperature under synthetic conditions not optimized for high emission.

Journal
Journal of the American Chemical Society
Volume
127
Issue
31
Year
2005
Start Page
10889
ISBN/ISSN
1520-5126; 0002-7863
DOI
10.1021/ja0437297