1. J. A. Mucha,Solid State Technol. p. 123, March 1985.
2. K. Kausche, M. Möller, and R. Plättner,Proc. 5th European Community Photovoltaic Solar Energy Conf., Athens 1983, W. Palz, ed., Reidel, Dordrecht (1983), p.707.
3. R. Primig and K. Rosan,Vacuum 36, 75 (1986).
4. J. P. M. Schmitt, J. Méot, P. Roubeau, and P. Parrens,Proc. 8th European Community Photovoltaic Solar Energy Conf., Florence 1983, I. Solomon, B. Equer, and P. Helm, eds., Kluwer Academic Publ., Dordrecht (1988), p.964.
5. C. J. Mogab, A. C. Adams, and D. L. Flamm,J. Appl Phys. 49, 3796 (1979).