Optical diagnosis on dusty plasmas for nanocrystalline thin film silicon solar cells
Summary
Thin film solar cells from hydrogenated silicon are viable solutions for mass production of electricity from solar energy. In the production of solar cells with plasma enhanced chemical vapour deposition (PECVD), the well-known effect of gas phase nucleation of silicon quantum dots can lead to the incorporation of nanocrystals resulting in improved optoelectronic properties. In this thesis, a stable and reproducible fluctuation of 10-50 Hz in emission and current was observed in dusty hydrogen-diluted silane plasmas. It was concluded that this fluctuation originates from the plasma dynamics caused by the growing dust particles. In the development of a new plasma reactor, also a substrate temperature calibration was done, in which was found that the substrate temperature is not only dependent on the heater temperature, but also on the substrate holder and the gas pressure. Finally, a setup for scattering experiments on dust particles (LLS) was developed and tested. With the setup using 90° scattering, a dust scattered signal was detected. A literature study on dusty plasmas is included in this thesis to provide a background for the continuation of the research project in the new reactor.