Imaging and spectroscopy of artificial-atom states in core/shell nanocrystal quantum dots.
Current imaging scanning tunneling microscopy is used to observe the electronic wave functions in InAs/ZnSe core/shell nanocrystals. Images taken at a bias corresponding to the s conduction band state show that it is localized in the central core region, while images at higher bias probing the p state reveal that it extends to the shell. This is supported by optical and tunneling spectroscopy data demonstrating that the s-p gap closes upon shell growth. Shapes of the current images resemble atomlike envelope wave functions of the quantum dot calculated within a particle in a box model.
Millo
O
O
Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
Katz
D
D
Cao
Y
Y
Banin
U
U