Type-I Ge∕Ge1−x−ySixSny strained-layer heterostructures with a direct Ge bandgap

The electronic properties of Ge∕Ge1−x−ySixSny strained-layer heterostructures are predicted theoretically. It is found that a lattice-matched system with fully strained Ge layers and relaxed Ge1−x−ySixSny alloys can have a direct fundamental bandgap with spatial localization in the Ge layers (type I). The Si and Sn concentrations for which such a direct bandgap obtains are close to those that have already been experimentally demonstrated [M. Bauer, C. Ritter, P. A. Crozier, J. Ren, J. Menendez, G. Wolf, and J. Kouvetakis, Appl. Phys. Lett. 83, 2163 (2003)]. The required level of tensile strain in the Ge layers is compatible with Si–Ge technology. The predicted direct bandgap values are as high as 0.6eV.

[1]  Syassen,et al.  Direct-band-gap absorption in germanium under pressure. , 1989, Physical review. B, Condensed matter.

[2]  Weber,et al.  Near-band-gap photoluminescence of Si-Ge alloys. , 1989, Physical review. B, Condensed matter.

[3]  J. Chelikowsky,et al.  Electronic Structure and Optical Properties of Semiconductors , 1989 .

[4]  Richard A. Soref,et al.  Direct-gap Ge/GeSn/Si and GeSn/Ge/Si heterostructures , 1993 .

[5]  F. Schäffler,et al.  Application of numerical exciton-wave-function calculations to the question of band alignment in S i / S i 1 − x Ge x quantum wells , 1999 .

[6]  Steven G. Louie,et al.  Computational design of direct-bandgap semiconductors that lattice-match silicon , 2001, Nature.

[7]  T. Pearsall.  Electronic and optical properties of Ge-Si superlattices , 1994 .

[8]  Martin,et al.  Theoretical calculations of heterojunction discontinuities in the Si/Ge system. , 1986, Physical review. B, Condensed matter.

[9]  Stefan Zollner,et al.  Ge–Sn semiconductors for band-gap and lattice engineering , 2002 .

[10]  Van de Walle Cg.  Band lineups and deformation potentials in the model-solid theory. , 1989 .

[11]  John Kouvetakis,et al.  Synthesis of ternary SiGeSn semiconductors on Si(100) via SnxGe1−x buffer layers , 2003 .

[12]  Ahmad Cn,et al.  Electron transport and pressure coefficients associated with the L1C and Delta 1C minima of germanium. , 1986 .

[13]  Corey L. Bungay,et al.  Tunable band structure in diamond–cubic tin–germanium alloys grown on silicon substrates , 2003 .

[14]  Christoph F. Reinhart,et al.  Type II band alignment in Si1-xGex/Si(001) quantum wells , 1997 .

[15]  M. Chandrasekhar,et al.  Effects of uniaxial stress on the electroreflectance spectrum of Ge and GaAs , 1977 .

[16]  David Smith,et al.  SnGe superstructure materials for Si-based infrared optoelectronics , 2003 .

[17]  M. McCartney,et al.  Simple chemical routes to diamond-cubic germanium-tin alloys , 2001 .

[18]  R. Soref,et al.  PREDICTED BAND GAP OF THE NEW SEMICONDUCTOR SIGESN , 1991 .

[19]  Jaros,et al.  Simple analytic model for heterojunction band offsets. , 1988, Physical review. B, Condensed matter.