Structural and electronic properties of wide band gap Zn 1-xMgxSe alloys

Journal of Applied Physics

Volumn 95, Issue 8, 2004, Pages 4184-4192

  Pelucchi, E ^a,e   Rubini, S ^a   Bonanni, B ^a,f   Franciosi, A ^a,b   Zaoui, A ^b   Peressi, M ^b   Baldereschi, A ^b,e   De Salvador, D ^c   Berti, M ^c   Drigo, A ^c   Romanato, F ^d  

^a LABORATORIO TASC   (Italy)

^b UNIVERSITY OF TRIESTE   (Italy)

^c UNIVERSITY OF PADOVA   (Italy)

^d SINCROTRONE TRIESTE   (Italy)

^e EPFL   (Switzerland)

^f UNIVERSITY OF TUSCIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

COMPOSITION; ELECTRONS; EXTRAPOLATION; OPTICAL WAVEGUIDES; PARAMETER ESTIMATION; PHOTOELECTRON SPECTROSCOPY; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SAMPLING; SECONDARY ION MASS SPECTROMETRY; SEMICONDUCTOR MATERIALS; SEMICONDUCTOR QUANTUM WELLS; SYNTHESIS (CHEMICAL); X RAY DIFFRACTION;

ACTIVE LAYERS; PSEUDOPOTENTIAL CALCULATIONS; QUATERNARY ALLOYS; WIDE BAND GAP;

ZINC ALLOYS;

EID: 2342481277     PISSN: 00218979     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.1682688     Document Type: Article

References (61)

1. S. Taniguchi, T. Hino, S. Itoh, K. Nakano, N. Nakayama, A. Ishibashi, and M. Ikeda, Electron. Lett. 32, 552 (1996).
2. E. Kato, H. Noguchi, M. Nagai, H. Okuyama, S. Kijima, and A. Ishibashi, Electron. Lett. 34, 282 (1998).
3. M. Strassburg, O. Schulz, U. W. Pohl, D. Bimberg, S. Itoh, K. Nakano, and A. Ishibashi, Electron. Lett. 36, 44 (2000).
4. H. P. Wagner, H.-P. Tranitz, W. Langbein, J. M. Hvam, G. Bacher, and A. Forchel, Phys. Status Solidi B 231, 11 (2002).
5. B. Bonanni, E. Pelucchi, S. Rubini, D. Orani, A. Franciosi, A. Garulli, and A. Parisini, Appl. Phys. Lett. 78, 434 (2001); E. Pelucchi, S. Rubini, B. Bonanni, A. Franciosi, and M. Peressi, ibid. 78, 1574 (2001).
6. B. Bonanni, E. Pelucchi, S. Rubini, D. Orani, A. Franciosi, A. Garulli, and A. Parisini, Appl. Phys. Lett. 78, 434 (2001); E. Pelucchi, S. Rubini, B. Bonanni, A. Franciosi, and M. Peressi, ibid. 78, 1574 (2001).
7. B. Jobst, D. Hommel, U. Lunz, T. Gerhard, and G. Landwehr, Appl. Phys. Lett. 69, 97 (1996).
8. H. Okuyama, Y. Kishita, and A. Ishibashi, Phys. Rev. B 57, 2257 (1998).
9. J. Puls, M. Rabe, A. Siarkos, and F. Henneberger, Phys. Rev. B 57, 14749 (1998).
10. B. Vögele, C. Morhain, B. Urbaszek, S. A. Telfer, K. A. Prior, and B. C. Cavenett, J. Cryst. Growth 201/202, 950 (1999).
11. M. Wörz, E. Griebl, Th. Reisinger, R. Flierl, B. Haserer, T. Semmer, T. Frey, and W. Gebhardt, Phys. Status Solidi B 202, 805 (1997).
12. The lattice parameter of ZnSe is 5.6687 Å, see J. Petruzzello, B. L. Greenberg, D. A. Cammack, and R. Dalby, J. Appl. Phys. 63, 2299 (1988).
13. M. Th. Litz et al., J. Cryst. Growth 159, 54 (1996).
14. U. Lunz, C. Schumacher, J. Schull, A. Gerhard, U. Schüssler, B. Jobst, W. Fashinger, and G. Landwehr, Semicond. Sci. Technol. 12, 970 (1997).
15. S. Adachi and T. Taguchi, Phys. Rev. B 43, 9569 (1991), report a ZnSe RT gap of 2.69 eV; U. Lunz, B. Jobst, S. Einfeldt, C. R. Becker, D. Hommel, and G. Landwehr, J. Appl. Phys. 77, 5377 (1995), found a ZnSe RT gap of 2.68 eV; while C. C. Kim and S. Sivananthan, Phys. Rev. B 53, 1475 (1996), report a RT gap of 2.711 eV. Our determination of the ZnSe RT band gap using optical absorption in transmission yielded 2.694 eV.
16. S. Adachi and T. Taguchi, Phys. Rev. B 43, 9569 (1991), report a ZnSe RT gap of 2.69 eV; U. Lunz, B. Jobst, S. Einfeldt, C. R. Becker, D. Hommel, and G. Landwehr, J. Appl. Phys. 77, 5377 (1995), found a ZnSe RT gap of 2.68 eV; while C. C. Kim and S. Sivananthan, Phys. Rev. B 53, 1475 (1996), report a RT gap of 2.711 eV. Our determination of the ZnSe RT band gap using optical absorption in transmission yielded 2.694 eV.
17. S. Adachi and T. Taguchi, Phys. Rev. B 43, 9569 (1991), report a ZnSe RT gap of 2.69 eV; U. Lunz, B. Jobst, S. Einfeldt, C. R. Becker, D. Hommel, and G. Landwehr, J. Appl. Phys. 77, 5377 (1995), found a ZnSe RT gap of 2.68 eV; while C. C. Kim and S. Sivananthan, Phys. Rev. B 53, 1475 (1996), report a RT gap of 2.711 eV. Our determination of the ZnSe RT band gap using optical absorption in transmission yielded 2.694 eV.
18. We are using here the temperature dependence of the MgSe band gap estimated by K. Watanabe, M. Th. Litz, M. Korn, W. Ossau, A. Waag, G. Landwehr, and U. Schüssler, J. Appl. Phys. 81, 451 (1997).
19. G. Kalpana, B. Palanivel, R. M. Thomas, and M. Rajagopalan, Physica B 222, 223 (1996).
20. R. Pandey and A. Sutjianto, Solid State Commun. 91, 269 (1994).
21. A. Zaoui, J. Phys.: Condens. Matter 14, 4025 (2002).
22. A. M. Saitta, S. de Gironcoli, and S. Baroni, Phys. Rev. Lett. 80, 4939 (1998).
23. A. M. Saitta, S. de Gironcoli, and S. Baroni, Appl. Phys. Lett. 75, 2746 (1999).
24. Sun-Ghil Lee and K. J. Chang, Phys. Rev. B 52, 1918 (1995).
25. Because we fabricated alloy epilayers thick enough to be fully relaxed, comparison should be made with the calculated properties of the free-standing superlattice.
26. I. Karpov, N. Venkateswaran, G. Bratina, W. Gladfelter, A. Franciosi, and L. Sorba, J. Vac. Sci. Technol. B 13, 2041 (1995).
27. Y. Fan, I. Karpov, G. Bratina, L. Sorba, W. Gladfelter, and A. Franciosi, J. Vac. Sci. Technol. B 14, 623 (1996).
28. Numerical Data and Functional Relationships in Science and Technology, edited by Landolt-Bornstein (Springer, New York, 1982), Group III, Vol. 17 a-b, 22 a.
29. A. T. Macrander, G. P. Schwartz, and G. J. Gualtieri, J. Appl. Phys. 64, 6733 (1988).
30. D. J. Dunstan, H. G. Colson, and A. C. Kimber, J. Appl. Phys. 86, 782 (1999).
31. K. Pinardi, Uma Jain, S. C. Jain, H. E. Maes, R. Van Overstraeten, and M. Willander, J. Appl. Phys. 83, 4724 (1998).
32. 12 elastic constants in MgSe were calculated in the plane-wave pseudopotential framework of DFT, by numerical differentiation of the stress tensor with respect to uniaxial cell deformation (±1%) in the (001) direction.
33. 12 elastic constants in MgSe were calculated in the plane-wave pseudopotential framework of DFT, by numerical differentiation of the stress tensor with respect to uniaxial cell deformation (±1%) in the (001) direction.
34. The lattice parameter for CdSe is 6.077 Å, as reported by N. Samarth, H. Luo, J. K. Furdyna, S. B. Qadri, Y. R. Lee, A. K. Ramdas, and N. Otsuka, Appl. Phys. Lett. 54, 2680 (1989).
35. J. J. Yeh and I. Lindau, At. Data Nucl. Data Tables 32, 1 (1985).
36. 1-xAs alloys. See C. Marinelli, L. Sorba, M. Lazzarino, D. Kumar, E. Pelucchi, B. H. Müller, D. Orani, S. Rubini, and A. Franciosi, J. Vac. Sci. Technol. B 18, 2119 (2000).
37. C. Cohen, J. A. Davis, A. V. Drigo, and T. E. Jackman, Nucl. Instrum. Methods Phys. Res. 218, 174 (1983).
38. Handbook of Modern Ion Beam Analysis, edited by J. R. Tesmer and M. Nastasi (Materials Research Society, Pittsburgh, 1995).
39. J. F. Ziegler, Stopping Power and Ranges of Ions in Matter (Pergamon, New York, 1977), Vol. 4.
40. For a detailed discussion of the RBS fitting procedure, see C. Bocchi, S. Franchi, F. Germini, A. Baraldi, R. Magnanini, D. De Salvador, M. Berti, and A. V. Drigo, J. Appl. Phys. 89, 4676 (2001).
41. We used a kinetic energy cutoff of 25 Ry for the plane-wave expansion, special points Brillouin zone sampling (six special points within the irreducible wedge for the zinc blende structure, and almost equivalent sets for all other structures), and norm-conserving pseudopotentials with the Zn 3d electrons treated as core electrons, and including nonlinear core corrections for the cations.
42. A. Zunger, S.-H. Wei, L. G. Ferreira, and J. E. Bernard, Phys. Rev. Lett. 65, 353 (1990); S.-H. Wei, L. G. Ferreira, J. E. Bernard, and A. Zunger, Phys. Rev. B 42, 9622 (1990).
43. A. Zunger, S.-H. Wei, L. G. Ferreira, and J. E. Bernard, Phys. Rev. Lett. 65, 353 (1990); S.-H. Wei, L. G. Ferreira, J. E. Bernard, and A. Zunger, Phys. Rev. B 42, 9622 (1990).
44. A. Baldereschi and M. Peressi, J. Phys.: Condens. Matter 5, B37 (1993); U. Tinivella, M. Peressi, and A. Baldereschi, ibid. 9, 11141 (1997).
45. A. Baldereschi and M. Peressi, J. Phys.: Condens. Matter 5, B37 (1993); U. Tinivella, M. Peressi, and A. Baldereschi, ibid. 9, 11141 (1997).
46. A. Garcia and M. Cohen, Phys. Rev. B 47, 4215 (1993).
47. A. Zaoui, M. Ferhat, B. Khelifa, J. P. Dufour, and H. Aourag, Phys. Status Solidi B 185, 163 (1994).
48. The supercell results showed significant variations as a function of composition and the specific supercell used, varying from +0.04 eV for the chalcopyrite structure to +0.8 eV for the luzonite structure, with intermediate values for the famatinite structure.
49. E=+0.7eV. We notice that this estimate should be taken with some caution, since it was obtained from the result for a single alloy composition and from binary gaps that differ by a much smaller amount than the difference of the experimental optical gaps.
50. W. Luo, S. Ismail-Beigi, M. L. Cohen, and S. G. Louie, Phys. Rev. B 66, 195215 (2002).
51. O. Zakharov, A. Rubio, X. Blase, M. L. Cohen, and S. G. Louie, Phys. Rev. B 50, 10780 (1994).
52. A. Fleszar, Phys. Rev. B 64, 245204 (2001).
53. Comparing the LDA gap reported here for ZnSe with the experimental value makes a self-energy correction of 1.5 eV seem too large. However, we point out that our pseudopotential for Zn was constructed treating the 3d electrons as core electrons and adding nonlinear core corrections. Treating the 3d electrons as valence electrons would have reduced the LDA gap for ZnSe to about 1 eV - see, for instance, W. Luo, S. Ismail-Beigi, M. L. Cohen, and S. G. Louie, Phys. Rev. B 66, 195215 (2002); A. Continenza, S. Massidda, and A. J. Freeman, ibid. 38, 12996 (1988) - so that a 1.5 eV self-energy correction would have become appropriate.
54. Comparing the LDA gap reported here for ZnSe with the experimental value makes a self-energy correction of 1.5 eV seem too large. However, we point out that our pseudopotential for Zn was constructed treating the 3d electrons as core electrons and adding nonlinear core corrections. Treating the 3d electrons as valence electrons would have reduced the LDA gap for ZnSe to about 1 eV - see, for instance, W. Luo, S. Ismail-Beigi, M. L. Cohen, and S. G. Louie, Phys. Rev. B 66, 195215 (2002); A. Continenza, S. Massidda, and A. J. Freeman, ibid. 38, 12996 (1988) - so that a 1.5 eV self-energy correction would have become appropriate.
55. A. Wall, Y. Gao, A. Raisanen, A. Franciosi, and J. R. Chelikowsky, Phys. Rev. B 43, 4988 (1991).
56. P. Y. Yu and M. Cardona, Fundamentals of Semiconductors (Springer, Berlin, 1996).
57. The LT gap was obtained by adding to the PL-derived exciton emission energy the exciton binding energy dependence on lattice parameter reported by M. Wörz, E. Griebl, Th. Reisinger, R. Flierl, B. Haserer, T. Semmer, T. Frey, and W. Gebhardt, Phys. Status Solidi B 202, 805 (1997).
58. The data of B. Jobst, D. Hommel, U. Lunz, T. Gebhardt, and G. Landwehr, Appl. Phys. Lett. 69, 97 (1996) show a pronounced nonlinearity in the dependence of the band gap on lattice parameter only for lattice parameters above 5.85 A. For lower lattice parameters a linear fit would be more accurate. For clarity, in Fig. 5 we used such a linear fit to replace the actual experimental points by Jobst et al.
59. M. P. Seah and W. A. Dench, Surf. Interface Anal. 1, 2 (1979).
60. In the kinetic-energy range of interest, the escape depth of normally emitted Zn 3d and Mg 2p photoelectrons is about 27 Å, see E. A. Kraut, R. W. Grant, J. R. Waldrop, and S. P. Kowalczyk, Phys. Rev. B 28, 1965 (1983). In our experimental geometry the average photoelectron collection angle is 55° from the sample normal, leading to an effective escape depth of about 15 Å.
61. The 4 MeV beam samples the whole II-VI layer and part of the GaAs substrate. The concentration value, on the other hand, was derived only by considering backscattering energies from 3000 to 3300 keV. This energy range roughly corresponds to the first 3000 Å of the sample [see J. F. Ziegler, Stopping Power and Ranges of Ions in Matter (Pergamon, New York, 1977), Vol. 4.