The Blue Laser Diode

Recently, we succeeded in producing for the first time, 1-cd-brightness blue InGaN/AlGaN light-emitting diodes (LEDs) suitable for commercial applications.1,5 In this report, co-doping with both Zn and Si into the InGaN active layer in InGaN/AlGaN LEDs in order to increase the output power of the InGaN/AlGaN LEDs is described.

InGaN/AlGaN blue light emitting diodes

Enhancing optical anisotropy of crystals by optimizing bonding electron distribution in anionic groups

Development work was conducted on N+PN+PN+ Poly silicon light-emitting devices which are compatible with silicon-based integrated circuit technology. We discuss the emission characteristics of visible light by a monolithically integrated Poly-Si diode under reverse bias. With the structure of modified PN junctions, the carriers injection occurs through silicon slabs of only a few nanometer thick. The dominant role of non-radiative recombination at the N+ and P+ contacts is diminished by confining the injected carriers around the PN junction’s interface in which avalanche takes place. The current-dependent optical radiation presents a broad spectrum in the 400- to 900-nm range. Although the emission efficiency is low due to silicon’s indirect bandgap, it is advantageous to utilize these devices in all-silicon optoelectronic integrated circuits (OIC’s).

Light emission from a poly-silicon device with carrier injection engineering

Linear and nonlinear optical properties in spherical quantum dots: Inversely quadratic Hellmann potential

Linear and nonlinear intra-conduction band optical absorption in (In,Ga)N/GaN spherical QD under hydrostatic pressure

Pressure-dependent of linear and nonlinear optical properties of (In,Ga)N/GaN spherical QD

In this paper, a simultaneous study of electric field and impurity's position effects on the ground-state shallow-donor binding energy in GaN│InGaN│GaN spherical quantum dot-quantum well (SQD-QW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated using variational approach within the framework of the effective-mass approximation. The numerical results show that: (i) the binding energy is strongly affected by the external electric field and the SQD-QW dimension, (ii) a critical value of spherical system's radius is obtained constituting the limit of three dimension confinement and spherical thin layer confinement and (iii) the Stark shift increases with increasing electric field and it is more pronounced around the position of the impurity corresponding to the binding energy maxima than in the spherical layer extremities.

Theoretical investigation of stark effect on shallow donor binding energy in InGaN spherical QD-QW

Using a variational approach, we perform a theoretical study of hydrostatic pressure effect on the ground-state of axial hydrogenic shallow-donor impurity binding energy in InGaN/GaN square quantum well wire (SQWWs) as a function of the side length within the effective-mass scheme and finite potential barrier. The pressure dependence of wire length, effective mass, dielectric constant and potential barrier are taken into account. Numerical results show that: (i) the binding energy is strongly affected by the wire length and the external applied pressure and (ii) its maximum moves to the narrow wire in particular for height pressure.

Pressure-dependent shallow donor binding energy in InGaN/GaN square QWWs

External electric field effect on the lowest-excited state in wurtzite (In,Ga)N–GaN spherical quantum dot is considered. By means of a traditional Ritz variational method within the effective-mass approximation and finite potential barrier, the lowest-excited state energy with and without the presence of the impurity is investigated. The normalized binding energy under electric field effect is also performed. Our numerical results are compared with the previous theoretical findings and show a good agreement with those concerning especially the ground-state for different semiconductors materials and different QDs-shapes.

Haddou El Ghazi

Papers

Linear and nonlinear intra-conduction band optical absorption in (In,Ga)N/GaN spherical QD under hydrostatic pressure

Pressure-dependent of linear and nonlinear optical properties of (In,Ga)N/GaN spherical QD

Theoretical investigation of stark effect on shallow donor binding energy in InGaN spherical QD-QW

Pressure-dependent shallow donor binding energy in InGaN/GaN square QWWs

Impurity binding energy of lowest-excited state in (In,Ga)N-GaN spherical QD under electric field effect