The local structure of Mn-doped Li2B4O7(001) was investigated using extendedX-ray absorption fine structure (EXAFS) at the Mn K edge and electron paramagnetic resonance (EPR). The location of the Mn dopant in a lithium tetraborate crystal is consistent with occupation of a site with strong oxygen coordination. The Mn–O bond lengths are similar to those observed with Mn doping of the icosahedral...

We demonstrate a modulation of thermoelectric power factor via a radial dopant inhomogeneity in B-doped Si nanowires. These nanowires grown via vapor-liquid-solid (VLS) method were naturally composed of a heavily doped outer shell layer and a lightly doped inner core. The thermopower measurements for a single nanowire demonstrated that the power factor values were higher than those of homogeneo...

Off-axis electron holography is an electron microscopy-based technique that allows the electrostatic and magnetic fields in and around a specimen to be measured with nm-scale resolution. The continuous reduction in the size of semiconductor devices means that information about the distribution of strain fields and active dopants at a nanometre scale is required in order to understand how these ...

In this paper, we present a detailed simulation study of the influence of quantum mechanical effects in the inversion layer on random dopant induced threshold voltage fluctuations and lowering in sub-100 nm MOSFETs. The simulations have been performed using a three-dimensional (3-D) implementation of the density gradient (DG) formalism incorporated in our established 3-D atomistic simulation ap...

Doped catalyst-free GaAs nanowires have been grown by molecular beam epitaxy with the gallium-assisted method. The spatial dependence of the dopant concentration and resistivity have been measured by Raman spectroscopy and four point electrical measurements. Along with theoretical considerations, the doping mechanisms have been revealed. Two competing mechanisms have been revealed: dopant incor...

One of the major challenges towards scaling electronic devices to the nanometre-size regime is attaining controlled doping of semiconductor materials with atomic accuracy, as at such small scales, the various existing technologies suffer from a number of setbacks. Here, we present a novel strategy for controlled, nanoscale doping of semiconductor materials by taking advantage of the crystalline...

Although vanadium dioxide (VO2) exhibits the most abrupt metal-to-insulator transition (MIT) properties near room temperature, present regulation of their MIT functionalities is insufficient owing to high complexity and susceptibility associated with V4+. Herein, we demonstrate a spark plasma-assisted reactive sintering approach simultaneously achieve in situ doping VO2 within largely short per...

We present and review dopant mapping examples in semiconductor device structures by electron holography and outline their potential applications for experimental investigation of two-dimensional (2D) dopant diffusion on the nanometer scale. We address the technical challenges of the method when applied to transistor structures with respect to quantification of the results in terms of the 2D p-n...

The formation of a Schottky barrier at the metal-semiconductor interface is widely utilised in semiconductor devices. With the emerging of novel Schottky barrier based nanoelectronics, a further microscopic understanding of this interface is in high demand. Here we provide an atomistic insight into potential barrier formation and band bending by ab initio simulations and model analysis of a pro...

In recent years, a great deal of attention has been focused on the development of quantum wire transistors as a means of extending Moore’s Law. Here we present, results of fully three-dimensional, self-consistent quantum mechanical device simulations of InAs tri-gate nanowire transistor (NWT). The effects of inelastic scattering have been included as real-space self-energy terms. We find that t...