Simulated [111] Si–SiGe terahertz quantum cascade laser

Lever, L.; Valavanis, Alexander; Ikonić, Z.; Kelsall, R. W.

doi:10.1063/1.2836023

Cited by 24 publications

(17 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prospects of developing such Si-based QCLs have been investigated theoretically. One approach stayed with the Si-rich SiGe/Si material system but instead of the conventional growth direction in (100), the structural orientation has been rotated to the [111] crystal plane [61]. Conduction band offset was calculated to be 160meV at the conduction band minima consisting of six-degenerate -valleys, sufficient for designing far IR QCLs.…”

Section: Conduction Band Si-based Qclsmentioning

confidence: 99%

The Intersubband Approach to Si-based Lasers

Sun¹

2010

Advances in Lasers and Electro Optics

View full text Add to dashboard Cite

Section: Conduction Band Si-based Qclsmentioning

confidence: 99%

The Intersubband Approach to Si-based Lasers

Sun¹

2010

Advances in Lasers and Electro Optics

View full text Add to dashboard Cite

“…Several theoretical studies of Si-based QCLs exist, [6][7][8][10][11][12][13] but none have accounted for coherent transport effects (i.e., quantum tunneling and interactions with optical fields). Although semiclassical scattering-transport models can give good agreement with experimental results, 1,14 they neglect tunneling across barriers, and can predict unrealistically large spikes in current density and gain when electrons scatter between spatially-extended subbands.…”

Section: -11mentioning

confidence: 99%

Extended density-matrix model applied to silicon-based terahertz quantum cascade lasers

et al. 2012

Self Cite

View full text Add to dashboard Cite

Silicon-based terahertz quantum cascade lasers (QCLs) offer potential advantages over existing III-V devices. Although coherent electron transport effects are known to be important in QCLs, they have never been considered in Si-based device designs. We describe a density matrix transport model that is designed to be more general than those in previous studies and to require less a priori knowlege of electronic bandstructure, allowing its use in semi-automated design procedures. The basis of the model includes all states involved in interperiod transport, and our steady-state solution extends beyond the rotating-wave approximation by including DC and counter-propagating terms. We simulate the potential performance of bound-to-continuum Ge/SiGe QCLs and find that devices with 4-5-nm-thick barriers give the highest simulated optical gain. We also examine the effects of interdiffusion between Ge and SiGe layers; we show that if it is taken into account in the design, interdiffusion lengths of up to 1.5 nm do not significantly affect the simulated device performance.

show abstract

“…[5] This gives a low gain coefficient and requires very thin layers to achieve quantum confinement. Alternative approaches, which avoid this problem include either moving to the (111) crystal orientation [6] or using the L-valleys in Ge-rich systems. [7] Charge transport simulations typically assume that abrupt changes in alloy composition are possible.…”

Section: Introductionmentioning

confidence: 99%

Growth variation effects in SiGe-based quantum cascade lasers

Valavanis¹,

Ikonić²,

Kelsall³

2009

J. Opt. A: Pure Appl. Opt.

View full text Add to dashboard Cite

Abstract. Epitaxial growth of SiGe quantum cascade (QC) lasers has thus far proved difficult, and nonabrupt Ge profiles are known to exist. We model the resulting barrier degradation by simulating annealing in pairs of quantum wells (QWs). Using a semiclassical charge transport model, we calculate the changes in scattering rates and transition energy between the lowest pair of subbands.We compare results for each of the possible material configurations for SiGe QC lasers. The effects are most severe in n-type (001) Si-rich systems due to the large effective electron mass, and in p-type systems due to the coexistence of light-and heavy-holes.The lower effective mass and conduction band offset of (111) oriented systems minimises transition energy variation, and a large interdiffusion length (L d = 1.49 nm) is tolerated with respect to scattering rate. Ge-rich systems are shown to give the best tolerance with respect to subband separation (L d = 3.31 nm), due also to their low effective mass.

show abstract

Simulated [111] Si–SiGe terahertz quantum cascade laser

Cited by 24 publications

References 22 publications

The Intersubband Approach to Si-based Lasers

The Intersubband Approach to Si-based Lasers

Extended density-matrix model applied to silicon-based terahertz quantum cascade lasers

Growth variation effects in SiGe-based quantum cascade lasers

Contact Info

Product

Resources

About