Non-linear model of electronic band structure to highly tensile-strained Germanium

Escalante, José M.; Gassenq, A.; Tardif, Samuel; Guiloy, K.; Pauc, N.; Rieutord, F.; Calvo, V.; Dias, G. O.; Rouchon, D.; Widiez, J.; Hartmann, J.-M.; Fowler, Daivid; Chelnokov, A.; Reboud, V.; Duchemin, Ivan; Niquet, Y.M.

doi:10.1109/group4.2015.7305955

Cited by 2 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have computed the direct band gap of germanium as a function of the uniaxial [100] loading using the tight-binding model of ref., 28 adapted to the case of uniaxial stress. 29 This tight-binding model was built on top of ab initio data and designed to reproduce the band structure of germanium under arbitrary strains in the ±5% range. Since this model targets the zero temperature band struc-ture, the calculated heavy-and light-hole bandgaps were corrected for room temperature effects using Varshni's model.…”

Section: Comparison With Theoretical Modelsmentioning

confidence: 99%

“…We have computed the direct band gap of germanium as a function of the uniaxial [100] loading using the tight-binding model of ref adapted to the case of uniaxial stress . This tight-binding model was built on top of ab initio data and designed to reproduce the band structure of germanium under arbitrary strains in the ±5% range.…”

Section: Comparison With Theoretical Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Germanium under High Tensile Stress: Nonlinear Dependence of Direct Band Gap vs Strain

Guilloy¹,

Pauc²,

Gassenq³

et al. 2016

ACS Photonics

View full text Add to dashboard Cite

Germanium is a strong candidate as a laser source for silicon photonics. It is widely accepted that the band structure of germanium can be altered by tensile strain so as to reduce the energy difference between its direct and indirect band gaps. However, the conventional gap deformation potential model most widely adopted to describe this transition happens to have been investigated only up to 1 % uniaxially loaded strains. In this work, we use a micro-bridge geometry to uniaxially stress germanium along [100] up to ε 100 = 3.3 % longitudinal strain and then perform electro-absorption spectroscopy. We accurately measure the energy gap between the conduction band at the Γ point and the light-and heavy-hole valence bands. While the experimental results agree with the conventional linear deformation potential theory up to 2 % strain, a significantly nonlinear behavior is observed at higher strains. We measure the hydrostatic and tetragonal shear deformation potential of germanium to be a = −9.1 ± 0.3 eV and b = −2.32 ± 0.06 eV and introduce a second order deformation potential. The experimental results are found to be well described by tight-binding simulations. These new high strain coefficients will be suitable for the design of future CMOS-compatible lasers and opto-electronic devices based on highly strained germanium.2

show abstract

Section: Comparison With Theoretical Modelsmentioning

confidence: 99%

Section: Comparison With Theoretical Modelsmentioning

confidence: 99%