Влияние внутренних отражателей на эффективность инфракрасных (850 нм) светодиодов

Investigated are IR light-emitting diodes with 850 nm radiation wavelength, based on AlGaAs/GaAs heterostructures grown by the method of MOC-hydride epitaxy with a Bragg reflector and additional “reflecting” layer Al0.9Ga0.1As, which ensures the decrease of optical losses of the generated radiation. Developed is the post growth technology for forming frontal ohmic contacts and for texturing the light-emitting surface, which ensures the decrease of ohmic losses and the increase of the radiation extraction efficiency from a crystal. External quantum efficiency of light-emitting diodes with two internal reflectors and surface texturing exceeded 9% at the current range 0.1-1.4A

Prediction of the Conditions of Chloride-Hydride Epitaxy of Ga1–yInyAs1–xPx Isoperiod Layers with GaAs and GaAs1–xPx

Multicomponent solid solutions of AIIIBV are increasingly used in optoelectronics, photonics, and other fields of science and technology. These are AlGaInN-based emitters, InGaAsP-based receivers, etc. In addition, these materials are widely used as buffer and isomorphic layers in general-purpose nanoheterostructures. The main methods of their production are gas-phase methods, such as chloride-hydride, MOS-hydride epitaxy, MBE. The development of optimal technological modes of multicomponent layers and structures, as a rule, takes a lot of time and is quite expensive. In this paper, the author proposed a method for modeling processes based on the basic physical and chemical laws of the crystallization processes of materials and the properties of AIIIBV compounds. The analysis and prediction of the processes of obtaining four-component solid solutions In1–yGayAs1–xPx, isoperiodic with GaAs, three-component solid solutions GaAs0,8P0,2 and GaAs0,6P0,4 were performed. The calculated modes have been experimentally implemented and the materials corresponding to the current level of quality have been obtained.

Высокоэффективные (EQE=37.5%) инфракрасные (850 нм) светодиоды с брэгговским и зеркальным отражателями

Developed and investigated are IR (850nm) light-emitting diodes based on AlGaAs/Ga(In)As heterostructures grown by the MOC-hydride epitaxy technique with multiple quantum wells in the active region and with a double optical reflector consisted of a multilayer Al0.9Ga0.1As/Al0.1Ga0.9As Bragg heterostructure and an Ag mirror layer. Light-emitting diodes with the external quantum efficiency (EQE) of 37.5% at current densities greater than 10A/cm2 have been fabricated.

Самоорганизация состава пленок Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-N, выращенных на гибридных подложках SiC/Si

Using spectral ellipsometry, Raman spectroscopy, and scanning microscopy with an X-ray spectrometer (EDS), the phenomenon of self-organized change in the composition of AlxGa1-xN epitaxial layers during their growth by chloride-hydride epitaxy (EDX) on SiC / Si (111) hybrid substrates was revealed. It was found that during the growth of AlxGa1-xN layers with a low, about 11-24% Al content, interlayers (domains) appear, consisting of AlGaN stoichiometric composition. A qualitative model has been proposed, according to which self-organization in composition arises due to the effect of two processes on the growth kinetics of the AlxGa1-xN film. The first process is associated with the competition of two chemical reactions proceeding at different rates. One of these reactions is the AlN formation reaction; the second is the reaction of GaN formation. The second process, closely related to the first, is the appearance of elastic compressive and tensile stresses during the growth of AlxGa1-xN films by the CGE method on SiC / Si (111). Both processes influence each other, which leads to a complex pattern of aperiodic changes in the composition over the thickness of the film layer. Keywords: A3B5 compounds, wide-gap semiconductors, AlGaN, AlN, GaN, silicon carbide on silicon, self-organization of the composition, HVPE method, solid solutions, heterostructures.

Диэлектрические и пироэлектрические свойства композитов на основе нитридов алюминия и галлия, выращенных методом хлорид-гибридной эпитаксии на подложке карбида кремния на кремнии

The microstructure, dielectric, and pyroelectric properties of AlxGa1-xN composite epitaxial layers grown on SiC / (111) Si substrates by chloride-hydride epitaxy are studied. In the process of layer growth, the phenomenon of spontaneous formation of heterojunctions was discovered. Based on AlxGa1-xN epitaxial layers, a material has been obtained which currently has one of the highest pyroelectric coefficients for crystals (or thin films) of aluminum nitride.

Исследование элементарных процессов МOC-гидридной эпитаксии наногетероструктур на основе арсенида галлия методом атомно-силовой микроскопии

Using atomic force microscopy, we studied the elementary processes of growing (Al, Ga, In) As heterostructures on misoriented GaAs (001) substrates by the method of MOC hydride epitaxy under reduced pressure. It was established that the growth of the epitaxial layers of GaAs and AlGaAs occurs according to a layered mechanism with the formation of macrosteps. The growth of pseudomorphic InGaAs / GaAs (001) layers also occurs by a layered mechanism with the formation of macrosteps. However, if the thickness of the pseudomorphic InxGa1-xAs / GaAs (001) layer exceeds a certain critical value depending on the molar fraction of InAs in the composition of the solid solution (x), the formation of growth defects in the form of three-dimensional islands, the density of which increases with increasing thickness, is observed on the surface of the InGaAs layer InGaAs layer. The formation of three-dimensional InGaAs islands is associated with the relaxation of elastic stresses in the pseudomorphic InGaAs / GaAs (001) layer according to the Stranski-Krastanov mechanism. Keywords: gallium arsenide, AlGaAs, InGaAs, MOC hydride epitaxy, defect formation, Stranski-Krastanov mechanism.

Исследование влияния легирования на переходные слои анизотипных гетероструктур на основе GaInAsP и InP, полученных методом МОС-гидридной эпитаксии

In the study of doped anisotypic heterostructures with layers of Ga(1-x)In(x)P(1-y)As(y) grown on InP substrates with a buffer layer of InP by MOC-hydride epitaxy, the presence of transition regions was detected in the Ga(1-x)In(x)P(1-y)As(y) layer on the substrate side for individual samples, across which the arsenic content (y) increased from the interface with the InP layer to the surface of the structure by the amount of (Δy) up to 0.15, and the content of elements of the third group (x) remained constant.