1. D. V. Lang, H. G. Grimmeis, E. Meijer, and M. Jaros, Phys. Rev. B 22, 3917 (1982).
2. V. Cazcarra and P. Zunino, J. Appl. Phys. 51, 4206 (1980).
3. C. Y. Kung, C. M. Liu, W. Hsu, and R. H. Horng, J. Appl. Phys. 83, 56 (1998).
4. Yu. A. Bykovskiĭ, G. M. Voronkova, V. V. Grigor’ev, et al., Fiz. Tekh. Poluprovodn. (St. Petersburg) 36, 794 (2002) [Semiconductors 36, 740 (2002)].
5. V. V. Voronkov, G. I. Voronkova, V. N. Golovina, et al., Fiz. Tekh. Poluprovodn. (Leningrad) 16, 892 (1982) [Sov. Phys. Semicond. 16, 572 (1982)].