Self-assembled zinc blende GaN quantum dots grown

Zinc blende ~ZB! GaN quantum dots have been grown by plasma-assisted molecular-beam epitaxy on AlN buffer layers using 3C-SiC~001! substrates. The two- to three-dimensional growth mode transition is studied by following the evolution of the reflection high-energy electron diffraction pattern. ZB GaN island layers are further examined by atomic force microscopy and transmission electron microscopy, extracting a mean island height of 1.6 nm and a mean diameter of 13 nm at a density of 1.331011 cm22. Embedded ZB GaN quantum dots show strong ultraviolet photoluminescence without any thermal quenching up to room temperature.SFERERegion Rhône-AlpesConsejo Nacional de Ciencia y Tecnologí

Overview of electrical power models for concentrated photovoltaic systems

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Control of the morphology transition for the growth of cubic GaN-AlN nanostructures

The Stransky–Krastanow growth mode of strained layers which gives rise to a morphology transition from two-dimensional layer to three-dimensional islands is studied in details for the cubic gallium nitride on cubic aluminum nitride ~GaN/AlN! system grown by molecular beam epitaxy. Besides the lattice parameter mismatch which governs this transition, we evidence the importance of two other parameters, namely the substrate temperature and the III/V flux ratio. Tuning each of these two parameters enables to control the strain relaxation mechanism of a GaN deposited onto AlN, leading to the growth of either quantum wells or quantum dots

Improvement of RTS Noise in HgCdTe MWIR Detectors

International audienceandom telegraph signal (RTS) noise is present in all bands of the infrared spectrum from lambda (c) = 2.5 mu m (short-wavelength infrared) to lambda (c) = 15.75 mu m (very long-wavelength infrared) and decreases the performance of infrared photodetectors. The main features of RTS noise such as the jump amplitude and RTS frequency are defined, and their dependence as a function of focal-plane array (FPA) temperature was measured for all bands of the infrared spectrum. Both of these features comply with a Boltzmann activation law , and their activation energies scale with the bandgap. Comparison of three different HgCdTe mid-wavelength infrared photodetector technologies was also performed, showing that the optimized n-on-p improvement of operability (AOP) and p-on-n high-operating-temperature technologies show a reduced number of pixels exhibiting RTS noise (by about two decades) in comparison with standard n-on-p technology

Self-assembled zinc blende GaN quantum dots grown

Zinc blende ~ZB! GaN quantum dots have been grown by plasma-assisted molecular-beam epitaxy on AlN buffer layers using 3C-SiC~001! substrates. The two- to three-dimensional growth mode transition is studied by following the evolution of the reflection high-energy electron diffraction pattern. ZB GaN island layers are further examined by atomic force microscopy and transmission electron microscopy, extracting a mean island height of 1.6 nm and a mean diameter of 13 nm at a density of 1.331011 cm22. Embedded ZB GaN quantum dots show strong ultraviolet photoluminescence without any thermal quenching up to room temperature

Self-assembled zinc blende GaN quantum dots grown by molecular-beam epitaxy

International audienc

Growth and characterization of self-assembled cubic quantum dots

Self-assembled cubic GaN quantum dots have been grown by plasma-assisted molecular-beam epitaxy on cubic AlN. Atomic force microscopy and transmission electron microscopy reveal islands of a mean height of 1.6 nm and a mean diameter of 13 nm. The influence of stacking faults on island nucleation is discussed. The quantum dots show ultraviolet photo- and cathodo-luminescence with no thermal quenching up to room temperature