Nonlinear Elasticity in Wurtzite GaN/AlN Planar Superlattices and Quantum Dots

• Authors: S. Łepkowski , J. Majewski , G. Jurczak
• Languages of publication: EN

Abstracts

EN

The elastic stiffness tensors for wurtzite GaN and AlN show a significant hydrostatic pressure dependence, which is the evidence of nonlinear elasticity of these compounds. We have examined how pressure dependence of elastic constants for wurtzite nitrides influences elastic and piezoelectric properties of GaN/AlN planar superlattices and quantum dots. Particularly, we show that built-in hydrostatic pressure, present in both quantum wells of the GaN/AlN superlattices and GaN/AlN quantum dots, increases significantly by 0.3-0.7 GPa when nonlinear elasticity is used. Consequently, the compressive volumetric strain in quantum wells and quantum dots decreases in comparison to the case of the linear elastic theory. However, the z-component of the built-in electric field in the quantum wells and quantum dots increases considerably when nonlinear elasticity is taken into account. Both effects, i.e., a decrease in the compressive volumetric strain as well as an increase in the built-in electric field, decrease the band-to-band transition energies in the quantum wells and quantum dots.

Keywords

EN

78.67.-n; 62.20.Dc; 62.50.+p

Discipline

• 78.67.-n: Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures(for magnetic properties of nanostructures, see 75.75.-c; for electronic transport in nanoscale structures, see 73.63.-b; for mechanical properties of nanoscale systems, see 62.25.-g)

• Journal: Acta Physica Polonica A
• Year: 2005
• Volume: 108
• Issue: 5
• Pages: 749-754

Dates

published

2005-11

received

2005-06-04

Contributors

author

S. Łepkowski

• Unipress, Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29, 01-142 Warszawa, Poland

author

J. Majewski

• Institute of Theoretical Physics, Warsaw University, Hoża 69, 00-681 Warszawa, Poland

author

G. Jurczak

• Institute of Fundamental Technological Research, Świętokrzyska 21, 00-049 Warszawa, Poland

References

• 1. M.D. Frogley, J.R. Downes, D.J. Dunstan, Phys. Rev. B, 62, 13612, 2000
• 2. S.W. Ellaway, D.A. Faux, Phys. Status Solidi B, 235, 437, 2003
• 3. S.W. Ellaway, D.A. Faux, J. Appl. Phys., 92, 3027, 2002
• 4. S.P. Lepkowski, J.A. Majewski, Solid State Commun., 131, 763, 2004
• 5. S.P. Lepkowski, J.A. Majewski, Acta Phys. Pol. A, 105, 559, 2004
• 6. G. Kresse, J. Furthmuller, Phys. Rev. B, 54, 11169, 1996
• 7. E. Anastassakis, Phys. Rev. B, 46, 13244, 1992
• 8. F. Bernardini, V. Fiorentini, Phys. Status Solidi B, 216, 391, 1999
• 9. S.P. Lepkowski, G. Jurczak, P. Dluzewski, T. Suski, in: GaN, AlN, InN and their Alloys, Eds. Ch. Wetzel, B. Gil, M. Kuzuhara, M. Manfra, Vol. 831, Mater Res. Soc. Symp. Proc., Warrendale (PA) 2005, p. E11.14

Identifiers

DOI

10.12693/APhysPolA.108.749