478 citations · 2.1k across the 25 of their papers we have counts for
15 papers · 1 filter
Electrical control of inter-layer excitons in van der Waals heterostructures
A. Chaves, J. G. Azadani, V. Ongun Özçelik +2
We investigate excitons in stacked transition metal dichalcogenide (TMDC) layers under perpendicularly applied electric field, herein MoSe/WSe van der Waals heterostructure…
Enhanced interlayer neutral excitons and trions in trilayer van der Waals heterostructures
Chanyeol Choi, Jiahui Huang, Hung-Chieh Cheng +11
Vertically stacked van der Waals heterostructures constitute a promising platform for providing tailored band alignment with enhanced excitonic systems. Here we report observations…
Nanoscale Charge Balancing Mechanism in Alkali Substituted Calcium-Silicate-Hydrate Gels
V. Ongun Özçelik, Claire E. White
Alkali-activated materials and related alternative cementitious systems are sustainable material technologies that have the potential to substantially lower CO emissions associ…
Infrared fingerprints of few-layer black phosphorus
Guowei Zhang, Shenyang Huang, Andrey Chaves +4
Black phosphorus is an infrared layered material. Its bandgap complements other widely studied two-dimensional materials: zero-gap graphene and visible/near-infrared gap transition…
High-performance planar nanoscale dielectric capacitors
V. Ongun Özçelik, S. Ciraci
We propose a model for planar nanoscale dielectric capacitor consisting of a single layer, insulating hexagonal boron nitride (BN) stripe placed between two metallic graphene strip…
Adsorption of Group-IV Elements on Graphene, Silicene, Germanene, Stanene: Dumbbell Formation
V. Ongun Özçelik, D. Kecik, E. Durgun +1
Silicene and germanene derivatives constructed from periodic dumbbell units play a crucial role in multilayers of these honeycomb structures. Using first-principles calculations ba…
Silicite: the layered allotrope of silicon
Seymur Cahangirov, V. Ongun Ozcelik, Angel Rubio +1
Based on first-principles calculation we predict two new thermodynamically stable layered-phases of silicon, named as silicites, which exhibit strong directionality in the electron…
The atomic structure of the phase of silicene on Ag(111)
Seymur Cahangirov, Veli Ongun Özçelik, Lede Xian +5
The growth of the reconstructed silicene on Ag substrate has been frequently observed in experiments while its atomic structure and formation mechanism i…
Stable single-layer honeycomb like structure of silica
V. Ongun Özçelik, S. Cahangirov, S. Ciraci
Silica or SiO, the main constituent of earth's rocks has several 3D complex crystalline and amorphous phases, but it does not have a graphite like layered structure in 3D. Our…
Self healing of vacancy defects in single layer graphene and silicene
V. Ongun Özçelik, H. Hakan Gurel, S. Ciraci
Self healing mechanisms of vacancy defects in graphene and silicene are studied using first principles calculations. We investigated host adatom adsorption, diffusion, vacancy form…
Nanoscale Dielectric Capacitors Composed of Graphene and Boron Nitride Layers: A First Principles Study of High-Capacitance at Nanoscale
V. Ongun Özçelik, S. Ciraci
We investigate a nanoscale dielectric capacitor model consisting of two-dimensional, hexagonal h-BN layers placed between two commensurate and metallic graphene layers using self-c…
Effects of charging and electric field on the properties of silicene and germanene
H. Hakan Gürel, V. Ongun Özçelik, S. Ciraci
Using first-principles Density Functional Theory calculations, we showed that electronic and magnetic properties of bare and Ti adatom adsorbed single-layer silicene and germanene,…
Superlubricity through graphene multilayers between Ni(111) surfaces
S. Cahangirov, S. Ciraci, V. Ongun Özçelik
A single graphene layer placed between two parallel Ni(111) surfaces screens the strong attractive force and results in a significant reduction of adhesion and sliding friction. Wh…
Self-assembly mechanisms of short atomic chains on single layer graphene and boron nitride
V. Ongun Özçelik, S. Ciraci
Nucleation and growth mechanisms of short chains of carbon atoms on single-layer, hexagonal boron nitride (h-BN), and short BN chains on graphene are investigated using first-princ…
Supercapacitors composed of graphene and boron nitride layers: A first-principles study
V. Ongun Özçelik, C. Ataca, S. Ciraci
We propose a model for nanoscale supercapacitor consisting of two-dimensional insulating BN layers placed between two commensurate and metallic graphene layers. First-principles De…