Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Deposition of amorphous silicon films by gas flow sputtering (GFS)

: Mahrholz, J.; Shikolenko, S.; Szyszka, B.; Jung, T.

Sinke, W. ; WIP - Renewable Energies, München; European Commission; UNESCO; World Council for Renewable Energy; International Photovoltaic Equipment Association:
24th European Photovoltaic Solar Energy Conference 2009. CD-ROM : The compiled State-of-the-Art of PV Solar Technology and Deployment. Proceedings of the International Conference held in Hamburg, 21-25 September 2009
München, 2009
ISBN: 3-936338-25-6
European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC) <24, 2009, Hamburg>
Fraunhofer IST ()

The objective of this work was the development of a high rate and low temperature up-scaled deposition process of semi conductive a-Si:H thin films for solar cell application. The investigations were done with a gas flow sputter source basing on the hollow cathode effect. For reduced ion bombardment defects of a-Si:H films during growth a permanent magnetic shielding was applied and in its effectiveness confirmed. A wide range and complex parameter field was studied by variation of pressure, power, frequency, gas composition and temperature. Film characterization was executed by FTIR, SIMS, XRD, SEM and photo conductivity measurements. The results are very promising and confirm that large area coating on a 150-500 mm scale with GFS technology seams readily available. High deposition rates in the range of 4.5 nm/s or 21 nm*m/min were demonstrated and first light-to-dark photo conductivities giving values of some 103. Typical films were smooth and structure less consisting of nano crystals in a size of 1-2 nm embedded in an amorphous silicon matrix. Nevertheless there are some challenges concerning especially the improvement of semi conductive quality of a-Si:H films, e.g. by decreasing the content of parasitic elements and of clustered/poly-hydride Si:H structures. Besides there is need of fine adjustment on ion energy.