1. Fischer and W. Pschunder, in Proceedings of the 10th IEEE Photovoltaic Specialists Conference, Palo Alto, CA (IEEE, New York, 1973), p. 404.
2. J. Schmidt, A. G. Aberle, and R. Hezel, in Proceedings of the 26th IEEE Photovoltaic Specialists Conference, Anaheim, CA (IEEE, NewYork, 1997), p. 13.
3. S. W. Glunz, S. Rein, W. Warta, J. Knobloch, and W. Wettling, in Proceedings of the 2nd World Conference on Photovoltaic Solar Energy Conversion, Vienna, Austria (WIP, Munich, 1998), p. 1343.
4. K. Bothe, J. Schmidt, and R. Hezel, in Proceedings of the 29th IEEE Photovoltaic Specialists Conference, New Orleans, LA (IEEE, New York, 2002), p. 194.
5. A. Herguth, G. Schubert, M. Kaes, and G. Hahn, in Proceedings of the 21st European Photovoltaic Solar Energy Conference, Dresden, Germany (WIP, Munich, 2006), p. 530.