Phonon mediated lifetimes in intersubband terahertz lasers

Menon, Vinod M.; Goodhue, W. D.; Karakashian, A. S.; Ram‐Mohan, L. R.

doi:10.1063/1.1311833

Cited by 17 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To obtain the IF dispersions in a MQW QCL, the isolatedstage boundary condition (BC) is generally assumed [7,11,13] (c N,+ = 0 and c N ,− = 0). However, this assumption leads to a discontinuity in the phonon potentials at the interfaces between adjacent stages [18], The IF potential in one stage (e.g., stage λ) is the combination of Φ i (q, z) in each region R i of the same stage, i.e., Φ λ (q, z) = Φ i (q, z), z ∈ R i .…”

Section: Phonon Confinementmentioning

confidence: 99%

“…The phonon quantization was included in the Monte Carlo simulation [8,9] of a superlattice QCL with each period containing one barrier and one well, and an enhancement in the electron-LO phonon scattering rates was obtained. On the other hand, several groups [10][11][12] argued that the phonon confinement could significantly increase the scattering rates in MQW structures, but so far there has been no systematic account of phonon confinement in transport simulations of MQW QCLs.…”

mentioning

confidence: 98%

See 1 more Smart Citation

Confined phonon scattering in multivalley Monte Carlo simulation of quantum cascade lasers

2008

View full text Add to dashboard Cite

We present a detailed investigation of the effects that optical phonon confinement has on the electronic transport properties of GaAs-based multiple-quantum-well (MQW) quantum cascade laser (QCL) structures. Both confined and interface phonon modes are included based on the macroscopic dielectric continuum model. Interface phonon dispersions are obtained using the transfer matrix method with periodic boundary conditions. Scattering rates of both Γ -and X-valley electrons by all the interface and confined phonon modes are calculated and fully incorporated in the multivalley Monte Carlo simulation of a deep-active-well 6.7 µm GaAs-based MQW QCL. We find that the inclusion of phonon confinement enhances the electron-phonon scattering rates and output current to a relatively small extent with respect to the bulk phonon approximation.

show abstract

Section: Phonon Confinementmentioning

confidence: 99%

mentioning

confidence: 98%

Confined phonon scattering in multivalley Monte Carlo simulation of quantum cascade lasers

2008

View full text Add to dashboard Cite

show abstract

“…Moreover, Rücker et al 14 and Lee et al 36 showed that the DC model accurately predicts the total scattering rates obtained by microscopic calculations. In view of the accuracy of the DC model in the scattering rate calculation and the simplicity of its implementation, the DC model has been widely used [16][17][18]22,27,37 to treat phonon confinement in MQW structures.…”

Section: Phonon Confinement Modelingmentioning

confidence: 99%

“…15 Williams and Hu 16 also showed that the total phonon scattering rates including confinement in one stage ͑three quantum wells͒ of two GaAs/ Al 0.3 Ga 0.7 As terahertz QCLs are very close to those obtained using GaAs bulk phonons, thanks to wide wells and thin low-Al barriers. On the other hand, calculations by Menon et al 17 indicated that the scattering rate 21 ͑levels 2 to 1͒ in a similar three-QW ͑quantum well͒ THz structure can be strongly enhanced due to phonon confinement, and Ref. 18 reported that, in step quantum-well structures using GaAs/ Al 0.25 Ga 0.75 As/ Al 0.4 Ga 0.6 As materials, the scattering rates with phonon quantization are more than an order of magnitude greater than the bulk GaAs rate.…”

Section: Introductionmentioning

confidence: 95%

Phonon confinement and electron transport in GaAs-based quantum cascade structures

Gao¹,

Botez²,

Knežević³

2008

Journal of Applied Physics

View full text Add to dashboard Cite

We present a detailed investigation of the effects that optical-phonon confinement has on the electronic transport properties of GaAs-based midinfrared multiple-quantum-well ͑MQW͒ quantum cascade lasers ͑QCLs͒. The macroscopic dielectric continuum model is used to describe the interface ͑IF͒ and confined ͑CF͒ optical phonon modes. Dispersions of the IF modes are obtained by using the transfer matrix method with periodic boundary conditions. Normalization coefficients of the IF and CF potentials are derived in detail for MQW structures consisting of arbitrary combinations of binary and ternary alloys. Interstage and intrastage scattering rates due to all the IF and CF modes are calculated for both ⌫and X-valley electrons. The IF and CF scattering processes, in addition to the electron-electron and intervalley phonon scattering, are fully incorporated into the multivalley Monte Carlo simulation of a deep-active-well 6.7 m GaAs-based MQW QCL. At both 77 K and room temperature, we find that phonon confinement enhances the electron-polar optical phonon scattering rates to a relatively small extent and induces minor corrections to the current, population inversion, and the electronic temperature with respect to the results obtained in the bulk-phonon approximation. Therefore, the bulk-phonon approximation in transport simulations of GaAs-based QCLs remains valuable due to its simplicity and high accuracy.

show abstract

“…[25][26][27] These calculations do not consider screening, however, which tends to decrease the scattering rates.…”

Section: B Numerical Aspectsmentioning

confidence: 99%

Relaxation of a kinetic hole due to carrier-carrier scattering in multisubband single-quantum-well semiconductors

2003

View full text Add to dashboard Cite

We describe a theoretical model for carrier-carrier scattering in an inverted semiconductor quantum well structure using a multisubband diagram. The model includes all possible nonvanishing interaction terms within the static screening approximation, and it enables one to calculate accurately the temporal evolution of the carrier densities and the gain following a perturbation by a short optical pulse. We present a theoretical formalism and detailed numerical calculations. The addition of more than one subband in each band as well as the use of all exchange terms yields several results. First, the degree of gain saturation is reduced while, at the same time, the recovery is faster as scattering events among different subbands take place. Also, carrier transfer between subbands is observed which modifies the overall carrier dynamics.

show abstract

Phonon mediated lifetimes in intersubband terahertz lasers

Cited by 17 publications

References 23 publications

Confined phonon scattering in multivalley Monte Carlo simulation of quantum cascade lasers

Confined phonon scattering in multivalley Monte Carlo simulation of quantum cascade lasers

Phonon confinement and electron transport in GaAs-based quantum cascade structures

Relaxation of a kinetic hole due to carrier-carrier scattering in multisubband single-quantum-well semiconductors

Contact Info

Product

Resources

About