Early detection of diabetes, a worldwide health issue, is key for its successful treatment. Acetone is a marker of diabetes, and efficient, non-invasive detection can be achieved with the use of nanotechnology. In this paper we investigate the effect of acetone adsorption on the electronic properties of silicon nanowires (SiNWs) by means of density functional theory.
We considered hydrogenated SiNWs grown along the [1 1 1] bulk Si axis, with group-III impurities (B, Al, Ga), for which both surface substitutional doping and functionalizing schemes are considered. We present an analysis of the adsorption configuration, energetics, and electronic properties of the undoped and doped SiNWs. Upon acetone adsorption, the SiNW without impurities becomes an n-type semiconductor, while most substituted/functionalized cases have their HOMO-LUMO gap tuned, which could be harnessed in optical sensors. Acetone is always chemisorbed, although for the case without impurities, and the Al- and Ga-functionalization schemes, the chemisorption is very weak. These nanostructures could be used for acetone capture and detection, which could lead to applications in the medical treatment of diabetes.
Oxides for new-generation electronics
Silicon nanowires as acetone-adsorptive media for diabetes diagnosis
Francisco De Santiago, José Eduardo Santana, Álvaro Miranda, Luis Antonio Pérez, Riccardo Rurali, Miguel Cruz-Irissona
From catalysis and flat panel displays to photovoltaics, transparent and conducting transition metal oxides are gaining momentum toward more sustainable and cost-efficient applications. Here it is shown that, without using phase-matching arrangements, bulk plasmons can be excited in continuous epitaxial films of metallic SrVO3 and SrNbO3, with plasma absorption edges at visible range, and tuned mainly by electron correlations and phonon dressing. Films can be made reflective or transparent at whish.
The nature of electron-electron and electron-lattice interactions in metallic oxides is revised. The common wisdom is that the strong correlations among electrons determine their properties. Here we argue that the unavoidable coupling between free electrons and the lattice in ionic materials leads to the formation of polarons. These are carriers dressed by a lattice distortion that travel with them and largely determine the transport and some optical properties.
The incorporation of the new peakness-enhancing fast Fourier transform compatible ipp procedure (ipp = inner-pixel preservation) into the recently published SM algorithm based on |ρ| [Rius (2020). Acta Cryst A76, 489–493] improves its phasing efficiency for larger crystal structures with atomic resolution data. Its effectiveness is clearly demonstrated via a collection of test crystal structures (taken from the Protein Data Bank) either starting from random phase values or by using the randomly shifted modulus function (a Patterson-type synthesis) as initial ρ estimate.
The research into insulating ferrimagnetic garnets has gained enormous momentum in the past decade. This is partly due to the improvement in the techniques to grow high-quality ultrathin films with desirable properties and the advances in understanding the spin transport within the ferrimagnetic garnets and through their interfaces with conducting materials. In recent years, we have seen remarkable progress in controlling the magnetization state of ferrimagnetic garnets by electrical means in suitable heterostructures and device architectures.
Systematic studies on polycrystalline Hf1–xZrxO2 films with varying Zr contents show that HfO2 films are paraelectric (monoclinic). If the Zr content is increased, films become ferroelectric (orthorhombic) and then antiferroelectric (tetragonal). HfO2 shows very good insulating properties and it is used in metal-oxide-semiconductor field-effect devices, while ZrO2 shows good piezoelectric properties, but it is antiferroelectric. In between, Hf0.5Zr0.5O2 shows good ferroelectric properties at the expense of poorer insulating and piezoelectric properties than HfO2 and ZrO2, respectively.