A gate-tunable single-molecule diode

In the pursuit of down-sizing electronic components, the ultimate limit is the use of single molecules as functional devices. The first theoretical proposal of such a device, predicted more than four decades ago, is the seminal Aviram–Ratner rectifier that exploits the orbital structure of the molecule. The experimental realization of single...

Precise and reversible band gap tuning in single-layer MoSe2 by uniaxial strain

We present photoluminescence (PL) spectroscopy measurements of single-layer MoSe2 as a function of uniform uniaxial strain. A simple clamping and bending method is described that allows for application of uniaxial strain to layered, 2D materials with strains up to 1.1% without slippage. Using this technique, we find that the electronic band gap...

Heat-induced transformation of CdSe–CdS–ZnS core–multishell quantum dots by Zn diffusion into inner layers

In this work, we investigate the thermal evolution of CdSe–CdS–ZnS core–multishell quantum dots (QDs) in situ using transmission electron microscopy (TEM). Starting at a temperature of approximately 250 °C, Zn diffusion into inner layers takes place together with simultaneous evaporation of particularly Cd and S. As a result of this...

Unexpected origin of magnetism in monoclinic Nb12O29 from first-principles calculations

Nb12O29 is a 4d transition metal oxide that occurs in two forms with different symmetries, monoclinic (m) and orthorhombic (o). The monoclinic form has unusual magnetic properties; below a temperature of 12 K, it exhibits both metallic conductivity and antiferromagnetic ordering. Here, first-principles density-functional theory calculations are...

Localised corrosion in aluminium alloy 2024-T3 using in situ TEM

An approach to carry out chemical reactions using aggressive gases in situ in a transmission electron microscope (TEM), at ambient pressures of 1.5 bar using a windowed environmental cell, called a nanoreactor, is presented here. The nanoreactor coupled with a specially developed holder with platinum tubing permits the usage of aggressive...