1. Proc. of the 11 th European PVSEC;Aulich,1992
2. Proc. of the 11 th European PVSEC;Ichikawa,1992
3. R. van den Berg, H. Calwer, P. Marklstorfer, R. Meckes, F.W. Schulze, K.-D. Ufert and H. Vogt, Solar Energy Materials and Solar Cells to be published
4. Private communication, P. Sichanugrist
5. 21 th IEEE Photovoltaic Specialist Conference;Wieting,1990