Quantum dots (Q-dots) are particles whose
size is limited to a few nanometers.
More precisely, a Q-dot is a sphere with a
radius of few nm that can confine an electron in zero-dimension; hence the name
Makes Quantum Dots Interesting?
What makes Q-dots interesting is that their
physical properties are controlled by their small size. In semiconductor
research this has lead to novel applications in optoelectronics including
fluorescence, lasing, nonlinear optical effects, and other optoelectronic
applications such as ultra-fast switching.
It was in the early 80s when the first
Q-dots were successfully fabricated for the first time. Their fabrication is
based on the growth of a semiconductor crystal of atomic dimensions. The
construction of Q-dots took two separate paths. In one method the dot is
constructed using micro fabrication techniques, which has the disadvantage of
creating one Q-dot at a time. In the second method the Q-dots are grown by means
of a chemical reaction.
Figure 1. The upper image on the left hand side was measured with the Mobile S
AFM using a high resolution scan head. The white particles are 30nm large
Q-dots. The mono atomic terraces in the underlying surface are clearly visible
and prove the quality of the measurement.
Figure 2. The lower image on the left hand side is a zoom into the previous
image. It shows the perfectly round shape of the