MESA+ University of Twente
Mesa+ Meeting

Mesa+ - Meeting

1

Advanced materials & devices, chaired by dr.ir. Floris Zwanenburg

2

Fluidics & microsystems, chaired by dr.ir. Mathieu Odijk

3

Photonics & (bio)systems, chaired by dr.ir. Annemarie Huijser

4

Soft matter & devices, chaired by dr.ir. Wiebe de Vos

Advanced Materials & devices

Chair: Floris Zwanenburg (NanoElectronics)

INTRODUCTION

This parallel session focuses on the electronic properties of advanced nanoscale materials, varying from 2-dimensional materials such as silicene and MoS2 to superconducting Nb islands on Au. The presenters use different techniques to study their materials, in particular low-temperature electron transport measurements, in device and STM configuration and DFT calculations.

 

PROGRAM

11:45                  

Short introduction by Floris Zwanenburg (NE)

11:45

Nicola Poccia (ICE)           

Critical behavior at a dynamic vortex insulator-to-metal transition

12:00

Adil Acun (PIN) 

Group IV-materials beyond graphene: the growth of silicene studied with by low energy electron microscopy

12:15       

Frank Wiggers (NE)         

Silicene on h-BN terminated surfaces

12:30       

Mojtaba Farmanbar (CMS)          

Tuning the Schottky barrier heights at MX2/metal contacts

 

ABSTRACTS

 

Critical behavior at a dynamic vortex insulator-to-metal transition – Nicola Poccia (Interfaces and Correlated Electron Systems)

Superconducting vortices offer a unique tunable laboratory for studying classical critical dynamics. However, phase transitions and criticality far from equilibrium are less well understood respect their equilibrium counterpart. Using an array of superconducting islands placed on a normal metal film, we observed a vortex insulator–vortex metal transition driven by the applied electric current. Our findings offer a comprehensive description of dynamic critical behavior and establish a connection between equilibrium and non-equilibrium phase transitions.

 

Group IV-materials beyond graphene: the growth of silicene studied with by low energy electron microscopy – Adil Acun (Physics of Interfaces and Nanomaterials)

We have studied the formation and stability of silicene layers on Ag(111) by using low energy electron microscopy. Theoretical calculations show skepticism towards the stability of the graphene-like analog of silicon. We report that silicene layers are intrinsically unstable against the formation of “diamond-like” hybridized silicon structures. Thermal Si adatoms created by the silicene layer trigger the irreversible formation of the “sp3-like” hybridized silicon structure. The same instability hinders the formation of a fully closed silicene layer, making future large-scale fabrication promises of silicene layers on Ag-substrates unlikely.

Silicene on h-BN terminated surfaces Frank Wiggers (NanoElectronics)         

tbc

 

Tuning the Schottky barrier heights at MX2/metal contacts – Mojtaba Farmanbar (Computational Materials Science) 

The nature of the Schottky barrier at metal contacts with the two-dimensional semiconductor MX2 is controversial. Using first-principles DFT calculations we show that, one could control the Schottky barrier height at the interface by inserting a boron nitride (BN) monolayer between the metal surface and the MX2 layer. The BN layer disrupts the interaction between the metal surface and the MX2 layer and changes the metal work function, thereby enable us to reach a zero barrier for electrons or holes.