Fabrication and Characterization of In_0.25Ga_0.75N/GaN Multiple Quantum Wells Embedded in Nanorods

Abstract

The electrical resistivity of nickel alloys. if extrapolated to B = 0. depends on the angle between the current and the magnetization. We have measured. at 4.2 K. this resistivity anisotropy for ternar) alloys of general composition Ni,,A, -xBx, where A and B denote different metallic elements. These alloys include Ni(A1Cr). Ni(AuCo). Ni(AuRh). Ni(CoRh). Ni(CoRu). Ni(CrFe). Ni(CrMn). Ni(CrSn). Ni(CrTi), Ni(CuRh), Ni(CuRu). Ni(CuV). Ni(FePt). Ni(FeRe), Ni(RhRu) and Ni(RuTi).The experimental results have been analysed in terms of Mott's two current conduction model. In this model it is assumed that the conduction electrons of spin direction parallel or antiparallel to the magnetization contribute individually to the current. Each impurity element in nickel has got two residual resistivities, one for each spin current. We have derived thest residual resistivities for the ferromagnetic moment parallel and perpendicular to the current. It is found that the resistivity anisotropy is large for one of the spin currents (about + IOo,) while that for the other varies around -20".

Optical Properties of GaN Nanorods Containing a Single or Multiple InGaN Quantum Wells

“…Possible factors contributing to this increase in light output per unit volume are a reduction in non-radiative recombination when the nanorod diameter is less than the carrier diffusion lengths (typically $200{300 nm 11) ) and reduced light trapping in laterally propagating slab-like waveguide modes. 2) Further, there will be an increase in the optical matrix element arising from the increased overlap of the electron and hole wave functions as the QCSE decreases following lattice relaxation, giving rise to an increase in the internal quantum efficiency (IQE). 12) Figure 3 compares the room temperature PL from 230 nm diameter, vertically sided MQW nanorods formed after KOH etching with the electroluminescence (EL) from an LED comprising an array of nanorods of the same diameter fabricated from the same wafer.…”

“…InGaN/GaN nanorod light emitting diodes (LEDs) have recently attracted attention owing to the possibility that such nanostructures may accommodate strain to enhance the internal quantum efficiency by reducing the quantum confined Stark effect (QCSE) and, in addition, they could have enhanced light extraction efficiency. [1][2][3] Several mechanisms can contribute to the increased light extraction efficiency. For example, the emission may couple into the radiation modes of the nanorod as it acts as a waveguide for internally generated light.…”