We are researching alternative ways of preparing Si nanocrystals, here by crystallizing amorphous silicon using sharp tip in atomic force microscope (AFM). At pre-defined positions in the thin film of amorphous silicon, flowing electrical current creates microscopic pits exhibiting high conductivity. The high conductivity is attributed to the formation of silicon crystallites.
This has been confirmed by micro-Raman spectroscopy. Depending on the energy dose, the crystalline region can be in a form of dots or rings. We have optimized the procedure so that we achieved crystallites < 100 nm and microscopic matrices made of such crystallites. These achievements are promising for applications in many fields, from optoelectronics to nanobiotechnology. They also led to the issue of a national patent.
B. Rezek et al., Nanotechnology 20 (2009) 045302, also featured in NanoTechWeb and Materials Today LABORATORY OF FUNCTIONAL NANO-INTERFACES