A staff member of the LNF recently had a paper published pertaining to the controlled site selection of quantum dots in a stress-sensitive environment. The research studies the effects of external stresses and intermixing on single site-selected InAs/InP quantum dots in a highly scalable stress-sensitive environment. This project focused on nucleating InAs dots on in situ prepared nano-templates allowing for only epitaxial growth at deterministic locations on a silicon dioxide mask. This allowed for the growth of an InP pyramidal mesa with a point at the top, which was energetically favorable to nucleate a single InAs quantum dot, as shown in the figure to the right. The study of the strain profile across these dots as external stresses were applied to the pyramid’s apex resulted in the ability to red shift the wavelength of the dot. The intermixing of the dots yielded a blue shift in the dot’s wavelength. The combination of these two effects allows for spectral tuning of the quantum dots. The results of this research have implications in both quantum encryption and ultra-sensitive NEMs sensor applications.
To read the entire published article, visit:
http://scitation.aip.org/content/aip/journal/apl/103/6/10.1063/1.4817758
K. Mnaymneh, University of Michigan
D. Dalacu, R. L. Williams, National Research Council Canada, Ottawa