Abstract
In this study, the significant effect of the nonuniform composition in alloy quantum dots (QDs) on electronic structure is analyzed in depth. The equilibrium composition profiles in experimentally observed dome and barn shaped GeSi/Si QDs are determined by combining the finite element method and the method of moving asymptotes. Due to the composition variation, the total band edge of heavy hole is dominated by the band offset and spin-orbit coupling rather than the strain effect. The numerical results reveal that the wave function of heavy hole trends to be localized in the Ge-rich region at the top of the large QD. Moreover, the size effect gradually compensates the composition effect as the size of QD decreases.
Similar content being viewed by others
References
D. Bimberg, M. Grundmann, N.N. Ledentsov, Quantum Dot Heterostructures (Wiley, New York, 1999)
M. Zinke-Allmang, L.C. Feldman, M.H. Grabow, Surf. Sci. Rep. 16, 377 (1992)
G. Medeiros-Ribeiro, R.S. Williams, Nano Lett. 7, 223 (2007)
M.S. Leite, G. Medeiros-Ribeiro, T.I. Kamins, R.S. Williams, Phys. Rev. Lett. 98, 165901 (2007)
M. Hanke, D. Grigoriev, M. Schmidbauer, P. Schäfer, R. Köhler, R.L. Sellin, U.W. Pohl, D. Bimberg, Appl. Phys. Lett. 85, 3062 (2004)
M.I. Alonso, M. De la Calle, J.O. Ossó, M. Garriga, A.R. Goñi, J. Appl. Phys. 98, 033530 (2005)
U. Denker, M. Stoffel, J. Tersoff, G. Katsaros, G. Costantini, K. Kern, N.Y. Jean-Phillipp, D.E. Jesson, O.G. Schmidt, Phys. Rev. Lett. 94, 4 (2005)
A. Rastelli, M. Stoffel, A. Malachias, T. Merdzhanova, G. Katsaros, K. Kern, T.H. Metzger, O.G. Schmidt, Nano Lett. 8, 1404 (2008)
U. Denker, A. Rastelli, M. Stoffel, O.G. Schmidt, Phys. Rev. Lett. 90, 196102 (2003)
A. Lemaître, G. Patriarche, F. Glas, Appl. Phys. Lett. 85, 3717 (2004)
J.H. Blokland, M. Bozkurt, J.M. Ulloa, D. Reuter, A.D. Wieck, P.M. Koenraad, P.C. Christianen, J.C. Maan, Appl. Phys. Lett. 94, 023107 (2009)
C. Lang, D.J.H. Cockayn, D. Nguyen-Manh, Phys. Rev. B 72, 155328 (2005)
R. Gatti, F. Uhlik, F. Montalenti, New J. Phys. 10, 083039 (2008)
D. Digiuni, R. Gatti, F. Montalenti, Phys. Rev. B 80, 155436 (2009)
N.V. Medhekar, V. Hegadekatte, V.B. Shenoy, Phys. Rev. Lett. 100, 106104 (2008)
N.V. Medhekar, V. Hegadekatte, V.B. Shenoy, Solid State Commun. 149, 1395 (2009)
D.L. Wang, Z.Y. Yu, Y.M. Liu, H. Ye, P.F. Lu, L. Zhao, X.T. Guo, Chin. Phys. B 19, 086801 (2010)
H. Ye, P.F. Lu, Z.Y. Yu, D.L. Wang, Z.H. Chen, Y.M. Liu, S.M. Wang, Solid State Commun. 150, 1275 (2010)
X.D. Liang, Y. Ni, L.H. He, Comput. Mater. Sci. 48, 871 (2010)
A. Schliwa, M. Winkelnkemper, D. Bimberg, Phys. Rev. B 76, 205324 (2007)
M. Califano, P. Harrison, J. Appl. Phys. 91, 389 (2002)
W.Y. Tsai, K.B. Hong, M.K. Kuo, Phys. Status Solidi B 247, 1764 (2010)
M.Z. Hossain, N.V. Medhekar, V.B. Shenoy, H.T. Johnson, Nanotechnology 21, 095401 (2010)
M. Stoffel, A. Rastelli, J. Tersoff, T. Merdzhanova, O.G. Schmidt, Phys. Rev. B 74, 155326 (2006)
G. Medeiros-Ribeiro, A.M. Bratkovski, T.I. Kamins, D.A.A. Ohlberg, R.S. Williams, Science 279, 353 (1998)
K. Svanberg, Int. J. Numer. Meth. Eng. 24, 359 (1987)
F. Uhlik, R. Gatti, F. Montalenti, J. Phys.: Condens. Matter 21, 084217 (2009)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ye, H., Lu, P., Yu, Z. et al. Electronic structures of alloy quantum dots with nonuniform composition. Eur. Phys. J. B 81, 425–430 (2011). https://doi.org/10.1140/epjb/e2011-20153-7
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1140/epjb/e2011-20153-7