Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-20T07:02:12.276Z Has data issue: false hasContentIssue false
  • English
  • Français

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

Published online by Cambridge University Press:  10 February 2011

Harry A. Atwater ,
Regina Ragan  and
Kyu S. Min
Harry A. Atwater
Affiliation:
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology Pasadena, CA 91125, haa@daedalus.caltech.edu
Regina Ragan
Affiliation:
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology Pasadena, CA 91125, haa@daedalus.caltech.edu
Kyu S. Min
Affiliation:
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology Pasadena, CA 91125, haa@daedalus.caltech.edu
Get access

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.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 583 , 1999 , 349
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

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