Van der Waals heterostructures incorporating graphene, perovskites and other 2D materials

Lead Research Organisation: University of Manchester
Department Name: Physics and Astronomy

Abstract

For the past decade, halide perovskites have been subject to tremendous interest from the material science community, due to their potential use in high efficiency solar cells and bright light-emitting devices. Some key attributes of these perovskite materials include cheap fabrication processes, strong absorption coefficients and low non-radiative carrier recombination rates. Recently, the synthesis of 2D halide perovskite crystals have been achieved, demonstrating promising stability properties, as well as large carrier mobilities and intense photo- and electro-luminescence.

2D materials have triggered an unparalleled momentum, driving research on a new class of materials: van der Waals heterostructures, consisting in different 2D crystals stacked on top of each-others. These artificial materials present new and intriguing electronic properties, taking advantage of the absence of long-range order, 2D excitons or many-bodies instabilities such as superconductivity, and allowing observation of quantum relativistic phenomena.

This project aims at creating van der Waals heterostructures by stacking 2D halide perovskite crystals in heterostructures with graphene and studying the electronic properties of the assembly. The new devices are expected to have a number of technologically important properties and have a realistic potential to contribute to innovative semiconductor technologies.
 
Description van der Waals heterostructures combining graphene and boron nitride allow the creation of a periodic patterns called moiré superlattices. These superlattices change the electronic properties of the two materials with new fundamental physics emerging when combined. Particularly, we have shown that this allows the creation of new electronic states at high magnetic fields, through the ballistic propagation of a new family of quasiparticles : Brown-Zak fermions. We have shown the ballistic motions and straight trajectories of these quasiparticles, and studied the degeneracy with the introduction a new quantum number.

Other research on this award include discovery of electronic phase separation and quantum hall effect in van der Waals heterostructures made with multilayer graphite.
Exploitation Route The Brown-Zak fermions are new high quality metallic states. Studying their properties at low temperatures in more details could be of particular interest in condensed matter physics for new basic discoveries.
Applications could range from new electronic devices to high quality high frequency sources and detectors.
Sectors Electronics

URL https://physicsworld.com/a/new-family-of-quasiparticles-appears-in-graphene/
 
Description Oxford Instruments Virtual Roadshow 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Oxford Instruments Nanoscience Virtual Roadshow - show to oxford instruments collaborators & clients examples of research feasible with their equipments. Talks about Brown-Zak fermions in graphene superlattices.
invited twice.
Year(s) Of Engagement Activity 2020
URL https://nanoscience.oxinst.com/virtual-roadshow/manchester-roadshow
 
Description Pint of Science 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Pint of Science is a worldwide science festival in which researchers talk in local pub/café/space to share their scientific discoveries and projects with the general public.
Year(s) Of Engagement Activity 2019
URL https://pintofscience.co.uk/event/from-electrons-to-molecules
 
Description ballistic brown-zak fermions 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Press release + interviews about our research on Brown-Zak fermions:
https://physicsworld.com/a/new-family-of-quasiparticles-appears-in-graphene/
https://www.labnews.co.uk/article/2030972/graphene-team-hurls-physics-out-the-window
https://www.labnews.co.uk/article/2030993/a-research-story-advancing-mesoscopic-physics
https://www.sciencedaily.com/releases/2020/11/201113075240.htm
https://www.quora.com/q/sciencecommunication/Scientists-discover-new-family-of-quasiparticles-in-graphene-based-materials-A-group-of-researchers-have-discovered-and
https://medium.com/@sciencebulletin/scientists-discover-new-family-of-quasiparticles-in-graphene-based-materials-6fe73edb7a88
https://ground.news/article/cda66760-5602-40cd-8aec-35de27f9154d
https://scitechdaily.com/findings-to-help-achieve-holy-grail-of-2d-materials-superfast-electronic-devices/
https://www.eurekalert.org/pub_releases/2020-11/uom-mgd111220.php
https://scienmag.com/manchester-group-discover-new-family-of-quasiparticles-in-graphene-based-materials/
Year(s) Of Engagement Activity 2020
URL https://www.manchester.ac.uk/discover/news/manchester-group-discovers-radically-different-physics-in...