Haddou El Ghazi

Stark effect-dependent of impurity-related nonlinear optical absorption of a (In,Ga)N-GaN spherical quantum dot

The nonlinear intra-conduction band optical properties of a wurtzite (In,Ga)N-GaN spherical quantum dot are investigated. The linear, third-order nonlinear, and total absorption coefficients (ACs) of the 1s–1p transition are computed via a combination of the quantum genetic algorithm (QGA) and the Hartree–Fock–Roothaan (HFR) method. The external applied electric field effect is examined within the single-band effective mass and the one-parabolic-band approximations under a finite potential barrier. It is found that the electric field has a great impact on the optical properties of QDs: (i) a significant redshift of the resonant peak is obtained, (ii) the maximum of the amplitude of the optical total AC decreases nonlinearly, and (iii) the Stark shift increases nonlinearly, tending toward the saturation regime. Compared with findings, good agreement is shown.

Uncorrelated electron-hole transition Energy in GaN│InGaN│GaN Spherical QDQW Nanoparticles

The electron (hole) energy and uncorrelated 1Se 1Sh electron-hole transition in Core(GaN)j well(InxGa1 xN)j shell(GaN) spherical QDQW nanoparticles is investigated as a function of the inner and the outer radii. The calculations are performed within the framework of the eective-mass approximation and the nite parabolic potential connement barrier in which two conned parameters are taking account. The Indium composition eect is also investigated. A critical value of the outer and the inner ratio is obtained which constitutes the turning point of two indium composition behaviors.

Impurity-related nonlinear optical absorption under combined effects of intense laser field and band-edge nonparabolicity on InGaN QW

Conduction band-edge nonparabolicity effect on linear and nonlinear optical properties related to 1s–1p intra-conduction band transition in unstrained wurtzite (In, Ga)N–GaN symmetric quantum well (QW) is investigated incorporating an additional external probe as well as the nonresonant intense laser field (ILF) effect. Using the compact density matrix approach and the iterative procedure, the analytical expressions of optical absorption coefficients (ACs) are calculated. The numerical results are obtained within the single-band effective mass and the one-parabolic-band approximations under finite potential barrier. It is found that the internal and external perturbations show an important impact on the optical spectrum. A critical value of the laser-dressed parameter (LDP) is obtained by limiting two behaviors. Moreover, the ILF can be used as a way to control the optical properties of the QW structures and to reduce the lift of the conduction band-edge.

Conduction Band-Edge Non-Parabolicity Effects on Impurity States in (In,Ga)N/GaN Cylindrical QWWs

In this paper, the conduction band-edge non-parabolicity (NP) and the circular cross-section radius effects on hydrogenic shallow-donor impurity ground-state binding energy in zinc-blende (ZB) InGaN/GaN cylindrical QWWs are reported. The finite potential barrier between (In,Ga)N well and GaN environment is considered. Two models of the conduction band-edge non-parabolicity are taking into account. The variational approach is used within the framework of single band effective-mass approximation with one-parametric 1S-hydrogenic trial wave-function. It is found that NP effect is more pronounced in the wire of radius equal to effective Bohr radius than in large and narrow wires. Moreover, the binding energy peak shifts to narrow wire under NP effect. A good agreement is shown compared to the findings results.

Electric field effect on lowest excited-state binding energy of hydrogenic impurity in (In,Ga)N parabolic wire

Externally applied electric field and effective radius effects are investigated on the lowest excitedstate shallow-donor binding energy in (In,Ga)N-GaN parabolic wire within the framework of single band effective-mass approximation. The calculations are performed using the finite-difference method within the quasi-one-dimensional effective potential model. Our results reveal that: (i) the probability density is the largest on a circularity whose radius is the effective radius, (ii) the lowest excited-state binding energy is the largest for impurity located on this circularity while it starts to decrease when the impurity is away from the circularity and (iii) the binding energy is strongly-dependent on the complex interplay of spatial confinement, coulomb interaction and applied electric field.