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Based on the finite difference method, linear optical susceptibility, photoluminescence peak and binding energies of three first states of an exciton trapped by a positive charge donor-impurity ( ) confined in InN/AlN quantum well are investigated in terms of well size and impurity position. The electron, heavy hole free and bound excitons allowed eigen-values and corresponding eigen-functions are obtained numerically by solving one-dimensional time-independent Schrödinger equation. Within the parabolic band and effective mass approximations, the calculations are made considering the coupling of the electron in the n-th conduction subband and the heavy hole in the m-th valence subband under the impacts of the well size and impurity position. The obtained results show clearly that the energy, binding energy and photoluminescence peak energy show a decreasing behavior according to well size for both free and bound cases. Moreover, the optical susceptibility associated to exciton transition is strongly red-shift (blue-shifted) with enhancing the well size (impurity position).

In this paper, we study the hydrogen-like donor-impurity binding energy of the ground-state change as a function of the well width under the effect of temperature, size, and impurity position. Within the framework of the effective mass approximation, the Schrodinger-Poisson equation has been solved taken account an on-center hydrogen-like impurity in double QWs with rectangular finite confinement potential profile for 10% of indium concentration in the (well region). The eigenvalues and their correspondent eigenvectors have been obtained by the fined element method (FEM). The obtained results are in good agreement with the literature and show that the temperature, size, and the impurity position have a significant impact on the binding energy of a hydrogen-like impurity in symmetric double coupled quantum wells based on non-polar wurtzite (In,Ga) N/GaN core/Shell.

Intraconduction subband related optical absorption coefficient in non-polar m-plane symmetric linked (In,Ga)N/GaN double parabolic quantum wells is theoretically investigated in this study taking into consideration the presence of a single dopant hydrogen-like donor impurity moving down the growth axis. Calculations for a finite parabolic potential are performed using the impurity position, structural dimension, indium fraction, and temperature as adjusting variables. Using the finite difference approach, the Schrodinger equation is numerically solved to obtain the eigenvalues and their corresponding eigenvectors in the effective-mass approximation. The results reveal that increasing the coupling barrier and/or well concentration causes a considerable blueshift in the position of the absorption peak. Temperature, size change, and/or an impurity moving from the left band edge to the middle of the structure all cause a significant redshift in the absorption spectra. It has also been established that resonant optical absorption characteristics can be controlled by a careful choice of temperature and structure size, opening up new possibilities for high-performance infrared optical devices, optical modulators, solar cells, and laser applications.

In this paper, we theoretically investigate the impacts of Internal well composition, size and impurity's position on the inter valence-conduction bands and intra conduction band optical absorption in GaN/(In,Ga)N/GaN hetero-structure. Based on the numerically finite element method (FEM), the impurity's related Schrödinger equation is solved for the finite potential barrier considering the dielectric constant and effective-mass mismatches between the well and its surrounding matrix. Our results show that the absorption is strongly governed by the dipole matrix element and initial and final implied states transition energies. For a fixed barrier width, the absorption spectra are found red-shifted (blue-shifted) with increasing the well width (In-concentration). It is also shown that the impurity's absorption phenomenon is more pronounced for the off-center case compared to the on-center one. We conclude that the proper control of these parameters is required to best understanding of the optical absorption for solar cell applications.

The two-dimensional electron gas (2DEG) density modeling in WZ strained InN/GaN hetero-interface with Ga-face arrangement is considered in this paper. We theoretically investigate the role of an externally applied hydrostatic pressure and impurity's position by analyzing their impact in the presence of built electric field due to the dielectric mismatch between the system and its surrounding matrix. To solve the coupling Schrodinger-Poisson equations, as well as the polarization induced charges, finite element method code is used. Pressure-dependence of dielectric constant, band-gap energy, lattices and internal electric field is considered. The 2DEG appears to be strongly-dependent internal and external perturbations exhibiting a non-monotonic behavior. Our results prove that: (1) the InN channel is more populated for on-center impurity compared to off-center one, (2) the electron density in the triangular shape quantum well increases with the pressure; (3) the 2DEG density is enhanced versus the positive impurity's position and dropped versus pressure.