1. P.W. Kruse, Semiconductors and Semimetals 18, ed. R.K. Willardson and A.C. Beer, (New York: Academic Press, 1981), p. 9.
2. J.M. Kuo, S.S. Pei, S. Hui, S.D. Gunapala and B.F. Levine, J. Vac. Sci. Technol. B 10, 995 (1992).
3. S.D. Gunapala and K.M.S.V. Bandara, Homojunction and Quantum-Well Infrared Detectors ed. M.H. Francombe and J.L. Vossen, (New York: Academic Press Inc., 1995), p. 113.
4. R.L. Whitney, K.F. Cuff and F.W. Adams, Semiconductor Quantum Wells and Superlattices for Long-Wavelength Infrared Detectors, ed. M.O. Manasreh, (Artech House, 1993), p. 55; Christian Mailhiot, ibid, (1993), p. 109.
5. S.R. Kurtz and R.M. Biefeld, Pays. Rev. B 44, 1143 (1991).