1. L.P. Hunt, V.D. Dosaj, J.R. McCormick and L.D. Crossman, Proc. 12th IEEE Photovoltaic Specialists Conf. (IEEE, New York, 1976) p.125.
2. J.R. Davis, A. Rohatgi, P. Rai-Choudhury, P. Biais, R.H. Hopkins and J.R. McCormick, Proc.13th Photovoltaic Specialists Conf.(IEEE, New York, 1978), p.490.
3. T. Saitoh, N. Nakamura, H. Itoh, S. Matsubara, T. Warabisako and T. Tokuyama, ibid., p.479.
4. T. Warabisako, T. Saitoh, E. Kuroda, H. Itoh, N. Nakamura and T. Tokuyama, Japanese J. Appl.Phys.,19, Supplement 19–1, 539 (1980).
5. T.L. Chu, S.S. Chu, E.D. Stokes, C.L. Lin and R. Abderrassoul, Proc.13th IEEE Photovoltaic Specialists Conf. (IEEE, New York, 1978) p.1106.