Band parameters for GaAs and Si in the 24-k sdot p model

We present theory of the carrier-optical interaction in 1D systems based on the nonequilibrium Greens function formalism in the 4x4 k · p model. As a representative parameters we chose the GaAs. Although theory is presented in 4x4kp many subbands, results and discussion section is based on the simplified model such as 2x2 kp model (two transverse modes). Even though 2x2 kp model is simple enough it shows many phenomena that have not been seen before. We focus mainly on the ballistic extraction of photogenerated free carriers at the radiative limit which is described by the self-energy term derived in dipole approximation and solved in self-consistent manner with Keldysh quantum kinetic equations. Any relaxation or non-radiative recombination mechanisms as well as excitonic features are neglected.Effect of non-locality of electron-photon self energy term is considered and discussed.Spontaneous emission is also considered and shown to be small in short devices under medium bias conditions. Electron and hole spatial current oscillations are seen and discussed. It is shown that neglecting off-diagonal correlation in the band index not only produces quantitatively wrong results but it also alters the qualitative picture.All simulations are done in the full-rank approximation , with all spatial and band correlation effects are kept intact. This allows us to study not only quantitative effects but also qualitative behaviour.

Section: A Hamiltonianmentioning

confidence: 99%

Optoelectronic response calculations in the framework of k·p coupled to non-equilibrium Green's functions for one-dimensional systems in the ballistic limit

Buin

Verma

Saini

2013

“…Such a representation where all the relevant quantities are slowly varying continuous functions may lead one to believe that the model is a continuous one and that it cannot capture the full symmetry of the nanostructure. 31 The multiband kÁp Hamiltonians [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] are capable of reproducing the bulk band structure more accurately than the standard 8-band Hamiltonian. Some of these, that include a large number of bands (Z15 or 30 after incorporation of the spin degree of freedom), are even capable of reproducing the bulk band structure throughout the whole Brillouin zone.…”

Section: Introductionmentioning

confidence: 99%

Symmetry reduction in multiband Hamiltonians for semiconductor quantum dots: The role of interfaces and higher energy bands

Tomić¹,

Vukmirović²

2011

The role of interfaces and higher bands on the electronic structure of embedded semiconductor quantum dots (QDs) was investigated. The term in the multiband kÁp Hamiltonian that captures the effect of interface band mixing was derived starting from the microscopic theory. It was shown, analytically and numerically, that, with such a term included, the right symmetry of the QD system can be captured. It leads to splitting of otherwise degenerate energy levels of the order of several meV. The inclusion of additional higher bands beyond the ones from the standard eight-band model also leads to the reduction of symmetry from an artificially high one to the true atomistic symmetry of the system, however their quantitative effect is weaker. These results prove that the multiband kÁp Hamiltonians are fully capable of describing the correct symmetry of a QD.

“…[1][2][3][4][5][6][7][8][9] In all these references, the d levels are not taken into account. [1][2][3][4][5][6][7][8][9] In all these references, the d levels are not taken into account.…”

Section: Introductionmentioning

confidence: 99%

Band structures of AlAs, GaP, and SiGe alloys: A 30 k×p model

Fraj

Saïdi

Radhia

et al. 2007

The band structure of indirect-band gap semiconductors ͑AlAs, GaP͒ as well as indirect-band gap alloys semiconductors ͑GeSi͒ is described theoretically by using a 30ϫ 30 k ϫ p model including the d far-level contribution. For all materials investigated, the resulting electronic band structure parameters are in good agreement with experimental values. The method also provides a good description of the second conduction band which is useful for transport modeling. Finally, our results show that Luttinger parameters, the valence band parameter, and the effective masses in the X and L valleys are in good agreement with available experimental data.