We report on three-dimensional (3D) imaging of individual Gd dopant atoms in a thin (∼2.3  nm) foil of SrTiO3, using quantitative scanning transmission electron microscopy. Uncertainties in the depth positions of individual dopants are less than 1 unit cell. The overall dopant concentration measured from atom column intensities agrees quantitatively with electrical measurements. The method is a...

We have overcome the synthetic difficulty of 9,9',9'',9''',9'''',9'''''-((phenylsilanetriyl)tris(benzene-5,3,1-triyl))hexakis(9H-carbazole) (SimCP3) an advanced homologue of previously known SimCP2 as a solution-processed, high triplet gap energy host material for a blue phosphorescence dopant. A series of organic light-emitting diodes based on blue phosphorescence dopant iridium (III) bis(4,6-...

The influence of Fe2O3 additions on the microstructure, mechanical properties and translucence zirconia with 3 mol-% or 5 Y2O3 was evaluated. Samples were pressed different thickness sintered at 1475, 1500, 1550 1600°C for 2 h. Density, phases, roughness, strength translucency analyzed. All samples showed densification greater than 99%. After sintering 1600°C, phase analysis revealed only tetra...

We have developed an atomistic model for dopant diffusion in SiGe structures and we have implemented it in the kinetic Monte Carlo process simulator DADOS. The model takes into account (i) composition and stress effects on the diffusivity of interstitials, vacancies and dopants, (ii) SiGe interdiffusion, (iii) dopant segregation and (iv) the modifications of band-gap and charge levels. The mode...

Electron energy-loss spectroscopy (EELS) in combination with scanning transmission electron microscopy (STEM) reveals that the La enrichment at the surface of cerium-lanthanum solid solutions is an averaged effect and that segregation occurs in a mixed oxide phase. This separation occurs within a crystalline particle, where the dopant-rich phase is located at the surface of the dopant-deficient...

Quantitative ADF-STEM imaging paired with image simulations has proven to be a powerful technique for determining the three dimensional location of substitutionally doped atoms in thin films. Expansion of this technique to lightly-doped nanocrystals requires an understanding of the influence of specimen mistilt on dopant visibility due to the difficulty of accurate orientation determination in ...

We report the study of gold-SrTiO3 (STO)-gold memristors where the doping concentration in STO can be fine-tuned through electric field migration of oxygen vacancies. In this tunnel junction device, the evolution of the density of states (DOS) can be followed continuously across the metal-insulator transition (MIT). At very low dopant concentration, the junction displays characteristic signatur...

This paper presents findings on applying physical models in the literature to describe silicon luminescence spectra at 80 – 300 K. Incorporation of exciton recombination models are shown to disagree with the measured luminescence spectra, whereas a free electron-hole recombination model is shown to match well with the luminescence spectra. However, the lack of consideration for excitons is not ...

Semiconductor devices have been scaled to the point that transport can be dominated by only a single dopant atom. As a result, in a Si fin-type field effect transistor Kondo physics can govern transport when one electron is bound to the single dopant. Orbital (valley) degrees of freedom, apart from the standard spin, strongly modify the Kondo effect in such systems. Owing to the small size and ...

We present the first realization of three-dimensional lithography on the nanometer scale using atom optical techniques. It has already been shown that, with atom lithography, two-dimensional lateral structures of 50 nm can be obtained. In our experiment we utilize the resonant enhancement of light forces to address specifically one species of a multi-component beam. Thus a host and a dopant mat...