1. Smith, K. B., Gummel, H. K., Bode, J. D., Cuttriss, D. B., Nielsen, R. J., Rosenzweig, W., Bell. Sys. Tech. J. 42, 1765 (1963).
2. North, N. B., and Baker, B. F., Conf. Rec. 9th PVSC, Silver Springs, Maryland, 263 (1972).
3. For a review see: “The photovoltaic power and its application in space and on earth”, Proc. of the Congress “The Sun in the Service of Mankind”, July 2–6, Paris (1973).
4. Lehovec, K., Phys. Rev. 74, 463 (1948).
5. Tauc, J., “Photo and thermal effects in semiconductors”, Pergamon Press, Oxford (1962).