Georgios Kopidakis

Alloy engineering of excitonic properties in TMD monolayers

E. Katsipoulaki, Adlen Smiri, Panagiotis Spiliotakis, K. Mourzidis et autres

We investigate monolayer MoS$_{2x}$Se$_{2(1-x)}$ alloys across the full composition range using optical spectroscopy. We demonstrate continuous tuning of the optical gap over $\sim$0.35 eV, accompanied by a systematic reduction of the B--A exciton splitting, in agreement with density functional theory calculations. Temperature-dependent …

Alloy engineering of excitonic properties in TMD monolayers

E. Katsipoulaki, Adlen Smiri, Panagiotis Spiliotakis, K. Mourzidis et autres

We investigate monolayer MoS$_{2x}$Se$_{2(1-x)}$ alloys across the full composition range using optical spectroscopy. We demonstrate continuous tuning of the optical gap over $\sim$0.35 eV, accompanied by a systematic reduction of the B--A exciton splitting, in agreement with density functional theory calculations. Temperature-dependent …

gr, fr, jp, cz, cn (code pays fourni par la source)

Spontaneous Phase Separation in Polymer Solution by Janus Nanoparticle Compatibilizers: An Atomistic Molecular Dynamics Study

Dimitrios Stefanakis, Albert J. Power, Georgios Kopidakis, Vagelis Harmandaris et autres

High Resolution Image Download MS PowerPoint Slide We perform atomistic molecular dynamics simulations in order to investigate the structural and dynamic properties of Janus gold nanoparticles within diverse solvent environments, specifically pure polyethylene, pure water, and mixed polyethylene/water matrices. The nanoparticles, approximately …

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Interfacial engineering of p-n β-Co(OH)2/CdIn2S4 heterojunctions for efficient alkaline oxygen evolution electrocatalysis

Maria S. Metaxa, Ioannis Vamvasakis, Georgios Kopidakis, Γ. Κιοσέογλου et autres

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Spin‐Valley Polarization Control in WSe2 Monolayers using Photochemical Doping

E. Katsipoulaki, K. Mourzidis, Vishwas Jindal, Delphine Lagarde et autres

Abstract The influence of a photochemical doping method on the spin‐valley polarization degree (Pc) of excitons in WSe2 monolayers is reported. By varying the carrier density and transitioning from an excess of electrons (n‐type) to an excess of holes (p‐type), a non‐monotonic …

gr, fr, jp, ru (code pays fourni par la source)

Spin-valley polarization control in WSe$_2$ monolayers using photochemical doping

E. Katsipoulaki, K. Mourzidis, V. K. Jindal, David Lagarde et autres

We report on the influence of a photochemical doping method on the spin-valley polarization degree ($P_{c}$) of excitons in WSe$_2$ monolayers. By varying the carrier density and transitioning from an excess of electrons (n-type) to an excess of holes (p-type), we observe …

(3-CF3pyH)2(3-CF3py)Pb3I8: A Three-Dimensional Metal Halide Inorganic Framework with Distinctive Kagomé Bands

Rafaela Maria Giappa, N. I. Selivanov, Anna Yu. Samsonova, Apostolos Pantousas et autres

The structural diversity inherent in hybrid organic–inorganic metal halides as a function of the organic cation template can give access to numerous semiconducting materials featuring distinct polyhedral connectivity patterns. Beyond the common corner-sharing pattern of halide perovskites, different motifs can be accessed …

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Size Dependent Photocatalytic Activity of Mesoporous ZnIn2S4 Nanocrystal Networks

Evangelos K. Andreou, Ioannis Vamvasakis, Andreas Douloumis, Georgios Kopidakis et autres

High Resolution Image Download MS PowerPoint Slide Understanding of the band-edge electronic structure and charge-transfer dynamics in size-confined nanostructures is vital in designing new materials for energy conversion applications, including green hydrogen production, decomposition of organic pollutants and solar cells. In this …

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Electron density control in WSe2 monolayers via photochlorination

E. Katsipoulaki, Georgios Vailakis, Ιωάννα Δεμερίδου, Dimitrios Karfaridis et autres

Abstract Modulation of the Fermi level using an ultraviolet (UV)-assisted photochemical method is demonstrated in tungsten diselenide monolayers. Systematic shifts and relative intensities between charged and neutral exciton species indicate a progressive and controllable decrease of the electron density and switch tungsten …

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Electron density control in tungsten diselenide monolayers via photochlorination

E. Katsipoulaki, Georgios Vailakis, Ιωάννα Δεμερίδου, Dimitrios Karfaridis et autres

Modulation of the Fermi level using an ultraviolet (UV)-assisted photochemical method is demonstrated in tungsten diselenide monolayers. Systematic shifts and relative intensities between charged and neutral exciton species indicate a progressive and controllable decrease of the electron density and switch tungsten diselenide …

gr, jp (code pays fourni par la source)

Modulating interfacial charge redistribution of Ni2P/CuCo2S4 p-n nano-heterojunctions for efficient electrocatalytic overall water splitting

Sofia Bra, Ioannis Vamvasakis, Evangelos K. Andreou, Georgios Vailakis et autres

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Unfolding the band structure of van der Waals heterostructures

Georgios Vailakis, Georgios Kopidakis

Layer-by-layer stacking of two-dimensional materials results in van der Waals heterostructures (vdWH) of nanometer thickness and clean interfaces that often exhibit exceptional properties and present novel challenges. We perform first-principles calculations using density functional theory to examine the electronic properties of vdWH …

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