A theoretical approach aiming at the prediction of segregation of dopant atoms on nanocrystalline systems is discussed here. It considers the free energy minimization argument in order to provide the most likely dopant distribution as a function of the total doping level. For this, it requires as input (i) a fixed polyhedral geometry with defined facets, and (ii) a set of functions that describ...

Abstract. Optical fibers are made of glass with different refractive indices in the (inner) core and the (outer) cladding regions. The difference in refractive index arises due to a rapid transition in the concentration of a dopant across the boundary between these two regions. Fibers are normally drawn from a heated glass preform, and the different dopant concentrations in the two regions will...

Monolayer contact doping (MLCD) is a modification of the monolayer doping (MLD) technique that involves monolayer formation of a dopant-containing adsorbate on a source substrate. This source substrate is subsequently brought into contact with the target substrate, upon which the dopant is driven into the target substrate by thermal annealing. Here, we report a modified MLCD process, in which w...

This paper presents results obtained when using scanning nonlinear dielectric microscopy (SNDM) to measure dopant profiles in transistors. Secondary ion mass spectrometry (SIMS) measurements of an epitaxial multilayer film on a standard sample and SNDM measurements of the sample surface showed that it was possible to obtain a uniform concentration region with a thickness of approximately 4–5 μm...

Besides common implant techniques, dopant diffusion enables steep diffusion profiles in heavily doped deep-source drain and ultra-shallow junctions as required in advanced microelectronic technology. Experimental phosphorus dopant diffusion profiles in silicon are described by a rational function diffusion (RFD) model, based on direct solution of Fick’s equations and suitable for actual work in...

Irreversible optical sensing of humidity by a doped cholesteric liquid crystal is achieved by using a thin film of nematic host E7 with a binaphthylorthosilicate ester as dopant (guest). The film changes its color from blue (to green to orange to red) to colorless when exposed to humidity as the dopant is hydrolyzed.

Both Fe3 + and Fe2 + ions occur in FeCl3-doped polyacetylene. At low dopant levels ( < 0.01 mole frac­ tion) both Fe2 + and Fe3 + io'ns are paramagnetic down to 4.2 K. At dopant levels > 0.01 mole fraction, there is evidence from Mossbauer spectroscopy that Fe2+ ions associate into aggregates which are magneti­ cally ordered below 25 K. Aggregate formation appears to correlate with high electri...

It is now possible to create atomically thin regions of dopant atoms in silicon patterned with lateral dimensions ranging from the atomic scale (angstroms) to micrometers. These structures are building blocks of quantum devices for physics research and they are likely also to serve as key components of devices for next-generation classical and quantum information processing. Until now, the char...

We report on an extensive spectroscopic investigation of the impact of substitutional doping on the optoelectronic properties of PbS colloidal quantum dot (CQD) solids. N-doping is provided by Bi incorporation during CQD synthesis as well as post-synthetically via cation exchange reactions. The spectroscopic data indicate a systematic quenching of the excitonic absorption and luminescence and t...