konstai

• Mitra, Richa; Iordanidou, Konstantina; Shetty, Naveen; Hoque, Md Anamul; Datta, Anushree & Kalaboukhov, Alexei [Vis alle 10 forfattere av denne artikkelen] (2026). Gate-tunable negative differential resistance in multifunctional van der Waals heterostructure. Scientific Reports. 16(1). doi: 10.1038/s41598-026-68365-1. Fulltekst i vitenarkiv
• Larsen, Aleksander Amble; Gorantla, Sandeep; Nguyen, Phuong Dan; Rosnes, Andreas; Xu, Yijiang & Iordanidou, Konstantina [Vis alle 10 forfattere av denne artikkelen] (2026). Atomic-Resolution EDS Characterization of Ordering in a β–Cu–Zn–Al Alloy. Metallurgical and Materials Transactions A. ISSN 1073-5623. doi: 10.1007/s11661-025-08093-9. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Atomic ordering in single-crystal β –Cu–Zn–Al, relevant to the martensitic transformation and functional properties, is investigated using analytical STEM. Atomic-resolution EDS along the [110] zone axis, where all Wyckoff positions are spatially resolved, reveals three chemically distinct site occupancies. Correlation with HAADF-STEM contrast provides real-space evidence consistent with L2 1 ordering. In agreement with experiments, first-principles calculations show a slight energetic preference for L2 1 over D0 3 , with finite-temperature free-energy calculations indicating that this preference persists at elevated temperatures.

• Carretero-Palacios, S.; Esteso, V.; Li, Y.; Kuthe, S.; Brevik, I. & Iordanidou, Konstantina [Vis alle 10 forfattere av denne artikkelen] (2025). Impact of metal oxidation on ice growth and melting. Physical review B (PRB). ISSN 2469-9950. 111(8). doi: 10.1103/physrevb.111.085407. Fulltekst i vitenarkiv Vis sammendrag

  In this paper, we investigate the Casimir-Lifshitz free energy mechanism that governs both ice growth and melting near metal surfaces, with a particular focus on the role of oxidation. Our study reveals that metals such as gold, iron, and aluminum induce incomplete premelting, resulting in micron-sized liquid water layers when in contact with ice. These layers could have significant implications for the defrosting of metallic surfaces. When exposed to water vapor at the triple point, aluminum and other metals can induce the formation of notably thick layers of either liquid water or ice, which can theoretically become infinitely thick if other interactions are disregarded. However, when aluminum undergoes oxidation to form alumina, its behavior changes dramatically. Alumina surfaces cause complete melting when in direct contact with bulk ice and result in only micron-sized layers of water or ice in vapor conditions. In contrast, magnetite, the oxidized form of iron, retains metalliclike behavior due to its high dielectric constant, similar to other metals, and continues to support thick layers of water or ice. This distinction highlights the significant influence of oxidation on the dynamics of ice growth and melting near different metal surfaces.

• Iordanidou, Konstantina; Lara-Avila, Samuel; Kubatkin, Sergey; Dash, Saroj & Wiktor, Julia (2024). Unlocking the Potential of 2D WTe2/ZrS2 van der Waals Heterostructures for Tunnel Field-Effect Transistors: Broken-Gap Band Alignment and Electric Field Effects. Chemistry of Materials. ISSN 0897-4756. 36(22), s. 11317–11325. doi: 10.1021/acs.chemmater.4c02738. Fulltekst i vitenarkiv Vis sammendrag

  Heterostructures composed of two-dimensional materials open new avenues for advancing semiconductor technology, particularly in the development of energy-efficient tunnel field effect transistors (TFETs). Here, we employ density functional theory calculations to investigate the electronic behavior of WTe2/ZrS2 heterostructures having diverse dimensions and arrangement motifs. Our simulations suggest that the topmost valence band of WTe2 overlaps with the bottommost conduction band of ZrS2, giving rise to the broken gap or type-III band alignment, which is favorable for fabricating TFETs. Using first-principles molecular dynamics simulations, the temperature effect on the electronic properties is studied, demonstrating that the broken gap band alignment is preserved at 300 K. Furthermore, the electronic properties of the heterostructures are shown to be affected by external electric fields: positive electric fields increase the overlap between the valence and conduction states, whereas negative electric fields lead to the opposite effect. Interestingly, a Rashba-type spin splitting is observed in the topmost valence band, and the Rashba energy is slightly influenced by the presence of external electric fields. Overall, our study sheds light on the inherent characteristics of WTe2/ZrS2 heterostructures and can be valuable for fabricating TFETs with optimal performance.

• Iordanidou, Konstantina & Persson, Clas (2021). Optoelectronic properties of coexisting InGaZnO4 structures. Materials Science in Semiconductor Processing. ISSN 1369-8001. 121. doi: 10.1016/j.mssp.2020.105297. Fulltekst i vitenarkiv Vis sammendrag

  Indium gallium zinc oxides (IGZO) have been developed for thin-film transistor technologies. In this work, we analyze the fundamental properties of crystalline InGaZnO4, considering all possible Ga/Zn atomic distribution patterns. Using the hybrid Hartree-Fock density functional approach, the most stable configurations are identified. The simulations reveal that the considered configurations are indirect band-gap semiconductors with highly dispersive conduction bands (CB) and very flat valence bands (VB). Thereby, the electron effective masses are light, contrary to the heavy hole effective masses. This implies a good electron mobility and suppressed hole mobility, and consequently a low off-state current that minimizes the power consumption in future InGaZnO4-based transistors. Coexistence of different configurations is not an issue for InGaZnO4 since they all present very similar optoelectronic properties.

• Iordanidou, Konstantina & Persson, Clas (2021). Stoner ferromagnetism in hole-doped CuM(IIIA)2 with M(IIIA) = Al, Ga, and In. ACS Applied Materials & Interfaces. ISSN 1944-8244. 13(25), s. 29770–29779. doi: 10.1021/acsami.1c00403. Fulltekst i vitenarkiv Vis sammendrag

  Using density functional theory calculations, we examine the effect of hole doping on the magnetic and electronic properties of CuMIIIAO2, with MIIIA = Al, Ga, and In. CuMIIIAO2 nonmagnetic semiconductors switch to ferromagnetic half-metals upon hole doping. For CuAlO2, the nonmagnetic-to-ferromagnetic transition occurs for hole densities of ∼7 × 1019/cm3. Ferromagnetism arises from an exchange splitting of the electronic states at the valence band edge, and it can be attributed to the high-lying Cu-d states. Hole doping induced by cation vacancies and substitutional divalent dopants is also investigated. Interestingly, both vacancies and nonmagnetic divalent dopants result in the emergence of ferromagnetism.

• Houssa, Michel; Meng, Ruishen; Iordanidou, Konstantina; Pourtois, Geoffrey; Afanas'ev, Valeri & Stesmans, Andre (2020). Doping-induced ferromagnetism in InSe and SnO monolayers. Journal of Computational Electronics. ISSN 1569-8025. doi: 10.1007/s10825-020-01535-0. Fulltekst i vitenarkiv
• Meng, Ruishen; Houssa, Michel; Iordanidou, Konstantina; Pourtois, Geoffrey; Afanas'ev, Valeri & Stesmans, Andre (2020). Two-dimensional Gallium and Indium Oxides from Global Structure Searching: Ferromagnetism and Half Metallicity via Hole Doping. Journal of Applied Physics. ISSN 0021-8979. 128(3). doi: 10.1063/5.0012103. Fulltekst i vitenarkiv
• Iordanidou, Konstantina; Houssa, Michel & Persson, Clas (2020). Carrier-mediated ferromagnetism in two-dimensional PtS2. RSC Advances. 10(2), s. 952–957. doi: 10.1039/c9ra09756b. Fulltekst i vitenarkiv Vis sammendrag

  Using first principles calculations based on density functional theory, we study the impact of hole doping on the magnetic and electronic properties of two dimensional PtS2. Although 2D PtS2 is intrinsically non-magnetic, a stable ferromagnetic phase is found for a wide range of hole densities, owing to the so-called Stoner instabilities. Besides spontaneous magnetization, half-metallicity is additionally observed. The majority and minority spin states exhibit insulating and metallic nature, respectively, allowing a fully polarized spin transport in 2D PtS2. Lastly, hole doping resulting from substitutional doping is investigated. For As-doped PtS2 shallow spin-polarized states close to the valence band edge are observed, and among all studied group-V dopants, As replacing S, is the most promising one to induce p-type conductivity and a subsequent ferromagnetic order in PtS2.

• Meng, Ruishen; Houssa, Michel; Iordanidou, Konstantina; Pourtois, Geoffrey; Afanas'ev, Valeri & Stesmans, Andre (2020). Ferromagnetism and half-metallicity in two-dimensional MO (M = Ga, In) monolayers induced by hole doping. PHYSICAL REVIEW MATERIALS. 4(7). doi: 10.1103/PhysRevMaterials.4.074001. Fulltekst i vitenarkiv
• Houssa, Michel; Iordanidou, Konstantina; Dabral, Ashish; Lu, Augustin; Pourtois, Geoffrey & Afanas'ev, Valeri [Vis alle 7 forfattere av denne artikkelen] (2019). Contact Resistance at MoS2-based 2D Metal/Semiconductor Lateral Heterojunctions. ACS Applied Nano Materials. 2(2), s. 760–766. doi: 10.1021/acsanm.8b01963. Fulltekst i vitenarkiv
• Houssa, Michel; Iordanidou, Konstantina; Dabral, Ashish; Lu, Augustin; Meng, Ruishen & Pourtois, Geoffrey [Vis alle 8 forfattere av denne artikkelen] (2019). Contact resistance at graphene/MoS2 lateral heterostructures. Applied Physics Letters. ISSN 0003-6951. 114(16), s. 163101-1–163101-5. doi: 10.1063/1.5083133. Fulltekst i vitenarkiv Vis sammendrag

  The contact resistance at two-dimensional graphene/MoS2 lateral heterojunctions is theoretically studied, using first-principles simulations based on density functional theory and the nonequilibrium Green's function method. The computed contact resistance lies in the range of 102 to 104 Ω μm, depending on the contact edge symmetry (armchair or zigzag) and termination (Mo and/or S terminated). This large variation in the contact resistance arises from the variation in the interface barrier height, which is sensitive to the presence of polar C-Mo bonds or sulfur dangling bonds at the interface. These results highlight that the control of the edge symmetry and/or edge termination is crucial to achieve a low contact resistance (in the range of a few hundred ohms micrometer) at graphene/MoS2 lateral heterojunctions for 2D material-based field-effect devices. Part of this work was financially supported by the KU Leuven Research Funds, Project No. C14/17/080, as well as the 2DFun project, an ERA-NET project in the framework of the Graphene Flagship. The authors acknowledge the support from Flanders Innovation and Entrepreneurship.

• Houssa, Michel; Meng, Ruishen; Iordanidou, Konstantina; Pourtois, Geoffrey; Afanas'ev, Valeri & Stesmans, Andre (2019). Stoner Ferromagnetism in Two-Dimensional Materials. ECS Transactions. ISSN 1938-5862. 92(1), s. 35–41. doi: 10.1149/09201.0035ecst. Fulltekst i vitenarkiv
• Hood, Samantha N; Walsh, Aron; Persson, Clas; Iordanidou, Konstantina; Huang, Dan & Kumar, Mukesh [Vis alle 10 forfattere av denne artikkelen] (2019). Status of materials and device modelling for kesterite solar cells. Journal of Physics: Energy. 1, s. 042004–042004. doi: 10.1088/2515-7655/ab2dda. Fulltekst i vitenarkiv Vis sammendrag

  Kesterite semiconductors, derived from the mineral Cu2(Zn,Fe)SnS4, adopt superstructures of the zincblende archetype. This family of semiconductors is chemically flexible with the possibility to tune the physical properties over a large range by modifying the chemical composition, while preserving the same structural backbone. In the simplest case, three metals (e.g. Cu, Zn and Sn) occupy the cation sublattice, which gives rise to a range of competing orderings (polymorphs) and the possibility for order–disorder transitions. The rich physics of the sulphide, selenide, and mixed-anion materials make them attractive for computer simulations in order to provide deeper insights and to direct experiments to the most promising material combinations and processing regimes. This topical review assesses the status of first-principles electronic structure calculations, optical modelling, and photovoltaic device simulations of kesterite semiconductors. Recent progress is discussed, and immediate challenges are outlined, in particular towards overcoming the voltage deficit in Cu2ZnSnS4 and Cu2ZnSnSe4 solar cells.

• Houssa, M.; Iordanidou, Konstantina; Pourtois, G.; Afanas'Ev, V.V. & Stesmans, A. (2018). Ferromagnetism in two-dimensional hole-doped SnO. AIP Advances. 8(5). doi: 10.1063/1.5025272. Fulltekst i vitenarkiv
• Iordanidou, Konstantina; Houssa, Michel; Kioseoglou, Joseph; Afanas’ev, Valeri; Stesmans, Andre & Persson, Clas (2018). Hole-Doped 2D InSe for Spintronic Applications. ACS Applied Nano Materials. 1(12), s. 6656–6665. doi: 10.1021/acsanm.8b01476. Fulltekst i vitenarkiv Vis sammendrag

  Using first-principles calculations based on density functional theory, we study the magnetic and electronic properties of hole-doped two-dimensional InSe. Our simulations reveal that although 2D InSe is intrinsically nonmagnetic, a stable ferromagnetic phase appears for a wide range of hole densities. Interestingly, hole doping induces not only spontaneous magnetization but also half-metallicity, and hole-doped InSe, presenting one conducting and one insulating spin channel, could be highly promising for next generation spintronic nanodevices. The possibility of inducing hole doping and a subsequent ferromagnetic order by intrinsic and extrinsic defects was also investigated. We found that In vacancy creates spin-polarized states close to the valence band and leads to a p-type behavior. Similar to In vacancies, group-V atoms replacing Se atoms lead to a p-type behavior, potentially stabilizing a ferromagnetic order in 2D InSe.

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