Subsequent projects | Special projects

Start of funding 01.01.2011

Precursor Methods for Silicon based Materials

Prof. Dr. Thomas F. Fässler
Technische Universität München

Prof. Dr. Susan M. Kauzlarich
University of California, Davis
Department of Chemistry


Beside wind power systems, represents solar energy the backbone of renewable energy concepts. A solar cell converts the energy of sunlight directly into electrical energy. Currently research investigations aim for an increase of the efficiency of the silicon based solar cell, which is principally used. Amorphous silicon (a-Si) has the largest share of the market of thin film solar cell despite their lower degree of efficiency of 5 % to 7 % if compared to crystalline silicon. In order to increase the efficiency a property improvement of this material class is necessary. In this context we develop strategies of chemical synthesis for the production alternative amorphous or nano-scaled silicon phases and their variation including the elements phosphorus and germanium. In this project we combine basic principles of chemical solid-state synthetic approaches with application-oriented synthetic concepts of material science.

Final report:
In the course of the above project, studies were carried out together with the group of Professor Susan Kauzlarich at the University of California at Davis, USA, in 2011 and 2012 and include the following travel and research work to and in the US:

• Professor Thomas Fässler (01.06.2011 – 31.07.2011): visit to Professor Susan M. Kauzlarich at the University of California at Davis, USA for the design of a protocol for the synthesis of silicon and germanium nanoparticles and the preparation of precursors.

• M.Sc. Markus Waibel (01.11.2011 – 01.12.2011): research stay at the University of California at Davis, USA, for experimental work in the group of Professor Susan M. Kauzlarich on the synthesis of silicon nanoparticles.

• M.Sc. Thomas Henneberger (17.11.2012 – 23.12.2012): research stay at the University of California at Davis, USA, for experimental work in the group of Professor Susan M. Kauzlarich on the synthesis of mixed silicon-germanium nanoparticles.

In the course of these studies, a synthesis protocol has been developed for the production of silicon and silicon-germanium nanoparticles.

In the meantime the technique for the synthesis of silicon nanoparticles developed in the course of these studies at the UC at Davis, USA, has successfully been transferred to the precursor compounds K12Ge17 and K12Si17-xGe17. The obtained products have been characterized by absorption and photoluminescence spectroscopy and studied by transmission electron microscopy. The results have been documented in an already completed PhD thesis (M. Waibel) and are part of another PhD thesis currently in progress. (Th. Henneberger).