Publications by Ahmet Avsar | EPFL Graph Search

Electrical spectroscopy of defect states and their hybridization in monolayer MoS2

Andras Kis, Oleg Yazyev, Yanfei Zhao, Juan Francisco Gonzalez Marin, Ahmet Avsar, Cheol Yeon Cheon, Kristians Cernevics, Zhenyu Wang, Mukesh Kumar Tripathi, Hyungoo Ji

Defects in solids are unavoidable and can create complex electronic states that can significantly influence the electrical and optical properties of semiconductors. With the rapid progress in the integration of 2D semiconductors in practical devices, it is ...

Nature Research2023

Engineering Optically Active Defects in Hexagonal Boron Nitride Using Focused Ion Beam and Water

Andras Kis, Aleksandra Radenovic, Georg Fantner, Evgenii Glushkov, Ahmet Avsar, Michal Daniel Macha, Vytautas Navikas, Aqeel Ahmed, Cheol Yeon Cheon, Nathan Cyprien Arsène Ronceray

Hexagonal boron nitride (hBN) has emerged as a promising material platform for nanophotonics and quantum sensing, hosting optically active defects with exceptional properties such as high brightness and large spectral tuning. However, precise control over ...

AMER CHEMICAL SOC2022

Excitonic devices with van der Waals heterostructures: valleytronics meets twistronics

Andras Kis, Ahmet Avsar, Alberto Ciarrocchi, Fedele Tagarelli

2D semiconducting transition metal dichalcogenides comprise an emerging class of materials with distinct properties, including large exciton binding energies that reach hundreds of millielectronvolts and valley-contrasting physics. Thanks to the van der Wa ...

2022

Anomalous interfacial dynamics of single proton charges in binary aqueous solutions

Aleksandra Radenovic, Jean Camille Benjamin Comtet, Evgenii Glushkov, Ahmet Avsar, Miao Zhang

Our understanding of the dynamics of charge transfer between solid surfaces and liquid electrolytes has been hampered by the difficulties in obtaining interface, charge, and solvent-specific information at both high spatial and temporal resolution. Here, w ...

AMER ASSOC ADVANCEMENT SCIENCE2021

Probing magnetism in atomically thin semiconducting PtSe2

Andras Kis, Oleg Yazyev, Michele Pizzochero, Ahmet Avsar, Alberto Ciarrocchi, Cheol Yeon Cheon, Mukesh Kumar Tripathi

Atomic-scale disorder in two-dimensional transition metal dichalcogenides is often accompanied by local magnetic moments, which can conceivably induce long-range magnetic ordering into intrinsically non-magnetic materials. Here, we demonstrate the signatur ...

Nature Research2020

Direct observation of water-mediated single-proton transport between hBN surface defects

Aleksandra Radenovic, Benoît Grosjean, Jean Camille Benjamin Comtet, Evgenii Glushkov, Ahmet Avsar

Super-resolution microscopy of defects in a two-dimensional material unveils the transport of single proton charges at solid/water interfaces. Aqueous proton transport at interfaces is ubiquitous and crucial for a number of fields, ranging from cellular tr ...

2020

Logic-in-memory based on an atomically thin semiconductor

Andras Kis, Aleksandra Radenovic, Yanfei Zhao, Ahmet Avsar, Zhenyu Wang, Guilherme Migliato Marega, Mukesh Kumar Tripathi

The growing importance of applications based on machine learning is driving the need to develop dedicated, energy-efficient electronic hardware. Compared with von Neumann architectures, which have separate processing and storage units, brain-inspired in-me ...

2020

Colloquium: Spintronics in graphene and other two-dimensional materials

Ahmet Avsar

After the first unequivocal demonstration of spin transport in graphene [Tombros et al., Nature (London) 448, 571-574 (2007)], surprisingly at room temperature, it was quickly realized that this novel material was relevant for both fundamental spintronics ...

2020

Excitonic device and operating methods thereof

Andras Kis, Dmitrii Unuchek, Ahmet Avsar, Alberto Ciarrocchi

The present disclosure concerns an excitonic device including at least one heterostructure comprising or consisting solely of a first two-dimensional material or layer and a second two-dimensional material or layer. The at least one heterostructure being c ...

2019

Valley-polarized exciton currents in a van der Waals heterostructure

Andras Kis, Dmitrii Unuchek, Ahmet Avsar, Alberto Ciarrocchi, Zhe Sun

2019

Defect induced, layer-modulated magnetism in ultrathin metallic PtSe2

Andras Kis, Oleg Yazyev, Dmitrii Unuchek, Michele Pizzochero, Ahmet Avsar, Alberto Ciarrocchi

2019

Thickness-modulated metal-to-semiconductor transformation in a transition metal dichalcogenide

Andras Kis, Dmitry Ovchinnikov, Ahmet Avsar, Alberto Ciarrocchi

Nature Research2018

Room-temperature electrical control of exciton flux in a van der Waals heterostructure

Andras Kis, Dmitrii Unuchek, Ahmet Avsar, Alberto Ciarrocchi

2018

Polarization switching and electrical control of interlayer excitons in two-dimensional van der Waals heterostructures

Andras Kis, Dmitrii Unuchek, Ahmet Avsar, Alberto Ciarrocchi

Nature Publishing Group2018

Reconfigurable Diodes Based on Vertical WSe2 Transistors with van der Waals Bonded Contacts

Andras Kis, Kolyo Marinov, Ahmet Avsar

Wiley2018

van der Waals Bonded Co/h-BN Contacts to Ultrathin Black Phosphorus Devices

Ahmet Avsar, Xin Luo

Because of the chemical inertness of two dimensional (2D) hexagonal-boron nitride (h-BN), few atomic-layer hBN is often used to encapsulate air-sensitive 2D crystals such as black phosphorus (BP). However, the effects of h-BN on Schottky barrier height, do ...

Amer Chemical Soc2017

Optospintronics in Graphene via Proximity Coupling

Andras Kis, Oriol López Sánchez, Dmitrii Unuchek, Ahmet Avsar

The observation of micrometer size spin relaxation makes graphene a promising material for applications in spintronics requiring long-distance spin communication. However, spin dependent scatterings at the contact/graphene interfaces affect the spin inject ...

American Chemical Society2017

Resolving the spin splitting in the conduction band of monolayer MoS2

Andras Kis, Kolyo Marinov, Ahmet Avsar

Time-reversal symmetry and broken spin degeneracy enable the exploration of spin and valley quantum degrees of freedom in monolayer transition-metal dichalcogenides. While the strength of the large spin splitting in the valance band of these materials is n ...

Nature Publishing Group2017

Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes

Ahmet Avsar

Two-dimensional materials offer new opportunities for both fundamental science and technological applications, by exploiting the electron's spin. Although graphene is very promising for spin communication due to its extraordinary electron mobility, the lac ...

Nature Publishing Group2017