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Formation of Direct Energy Gap Group IV Semiconductor Alloys and Quantum Dot Arrays in SnxSi1−x /Si and SnxGe1−x/Ge Alloy Systems

  • Harry A. Atwater (a1), Regina Ragan (a1) and Kyu S. Min (a1)

Abstract

The narrow gap semiconductor alloys SnxGe1−x, and SnxSi1−x offer the possibility for engineering tunable direct energy gap Group IV semiconductor materials. For pseudomorphic SnxGe1−x, alloys grown on Ge (001) by molecular beam epitaxy, an indirect-to-direct bandgap transition with increasing Sn composition is observed, and the effects of misfit on the bandgap analyzed in terms of a deformation potential model. Key results are that pseudomorphic strain has only a very slight effect on the energy gap of SnxGe1−x, alloys grown on Ge (001) but for SnxGe1−x alloys grown on Ge (111) no indirect-to-direct gap transition is expected. In the SnxSi1−x system, ultrathin pseudomorphic epitaxially-stabilized α-SnxSi1−x alloys are grown on Si (001) substrates by conventional molecular beam epitaxy. Coherently strained oa-Sn quantum dots are formed within a defect-free Si (001) crystal by phase separation of the thin SnxSi1−x layers embedded in Si (001). Phase separation of the thin alloy film, and subsequent evolution occurs via growth and coarsening of regularly-shaped α-Sn quantum dots that appear as 4–6 nm diameter tetrakaidecahedra with facets oriented along elastically soft [100] directions. Attenuated total reflectance infrared absorption measurements indicate an absorption feature due to the α-Sn quantum dot array with onset at ˜0.3 eV and absorption strength of 8 × 103 cm−1, which are consistent with direct interband transitions.

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[. He, G. and Atwater, H. A., Phys. Rev. Lett. 79,1937 (1997).
[. Jenkins, D.W. and Dow, J.D., Phys. Rev. B 36, 7994 (1987).
[. Wegscheider, W. et. al., J. Cryst. Growth 123, 75 (1992).
[. Ragan, R. and Atwater, H.A., submitted to Appl. Phys. Lett., 2000.
[. Bardeen, J. and Shockley, W., Phys. Rev. 80, 72 (1950).
[. People, R., Phys. Rev. 32, 1405 (1985).
[. Kleiner, W. H. and Roth, L.M., Phys. Rev. Lett. 2, 334 (1959).
[. Hasegawa, H., Phys. Rev. 129, 1029 (1963).
[. Pollak, F.H. and Cardona, M., Phys. Rev. 172, 816 (1968).
[0. Herring, C. and Voigt, E., Phys. Rev. 101, 944 (1956).
[1. Kang, N.L., Ryu, J.Y., and Choi, S.D., J. Phys. Soc. Jpn. 67, 2439 (1998).
[2. Pikus, G.E. and Bir, G.L., Fiz. Tverd. Tela 1, 1642 (1959) [Soy. Phys. (1960)].
[3. Min, K. S. and Atwater, Harry A., Appl. Phys. Lett. 72, 1884 (1998).
[4. Soref, R. A. and Perry, C. H., J. Appl. Phys. 69, 539 (1991).
[5. Apetz, R.. Vescan, L.. Hartmann, A.. Dieker, C., and Luth, H.. Appl. Phys. Lett. 66. 445 (1995)
[6. Sunamura, H., Usami, N., Shiraki, Y., and Fukatsu, S., Appl. Phys. Lett. 66, 3024 (1995).
[7. Swalin, R., Thermodynamics of Solids 2nd ed., (John Wiley and Sons, New York, 1972), p. 141.
[8. Krishnamurty, M., Drucker, J.S., and Venables, J.A., J. Appl. Phys. 69, 6461 (1991).
[9. Zinke-Allmang, M., Feldman, L.C., and Grabow, M.H., Sur. Sci. Rep. 16, 377 (1992).
[0. Eaglesham, D.J., White, A.E., Feldman, L.C., Moriya, N., and Jacobson, D.C., Phys. Rev. Lett. 70, 1643 (1993).

Formation of Direct Energy Gap Group IV Semiconductor Alloys and Quantum Dot Arrays in SnxSi1−x /Si and SnxGe1−x/Ge Alloy Systems

  • Harry A. Atwater (a1), Regina Ragan (a1) and Kyu S. Min (a1)

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