When studying quantum dots one of the most important properties
is the size of the band gap, and thus also their physical dimensions.
We investigated these properties for silicon quantum dots created
by means of plasma-enhanced chemical vapour deposition and annealing.
To determine the band gap size we measured photoluminescence
for ten dierent samples and to determine the physical
dimensions we used an atomic force microscope. The photoluminescence
measurements indicated that the intensity of the emitted
photons varied across the samples, but did not indicate any shift in
peak wavelength between samples nor any time-dependence of the
luminescence. The peak wavelength was in the order of 600 to 620
nm, corresponding to a band gap of 2.0 to 2.1 eV and a physical size
of approximately 3 nm. The AFM scans revealed densely packed
quantum dots, where few single objects could be distinguished. In
order to be able to perform a better statistical analysis, eorts would
have to be taken to separate the quantum dots.
2012. , 18 p.