Computing cluster
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Low-Dimensional Materials and Heterostructures
Figure 1 - 2D materials and hybrid heterostructures interacting with light
Image: Prof. Dr. Caterina CocchiWe aim to understand how structural and morphological degrees of freedom in low-dimensional materials and their heterostructures modify their electronic structure and interactions with light. To this end, we apply and extend methods based on density-functional theory and many-body perturbation theory. Systems of interest are transition-metal dichalcogenides and their interfaces with conjugated molecules.
Key developments
LayerPCM, an extension of the polarizable continuum model to describe the interaction between molecules and layered sustrates: https://pubs.aip.org/aip/jcp/article/154/22/224114/313403External link
Funded projects
- 2025 – 2028: DFG project “Valleytronics in van der Waals Heterostructures: breaking inversion symmetry with a twist (WHAT-A-TWIST)”
Relevant publications
- O. Ghaebi, T. Hamzayev, T. Weickhardt, M. S. Ramzan, T. Taniguchi, K. Watanabe, C. Cocchi, D. De Fazio, and G. Soavi, Tunable Exciton Modulation and Efficient Charge Transfer in MoS2/graphene van der Waals HeterostructuresExternal link, ACS Nano 19, 19027 (2025).
- H. C. Nerl, J. P. Guerrero-Felipe, A. M. Valencia, K. F. Elyas, K. Höflich, C. T. Koch, and C. Cocchi, Mapping the energy-momentum dispersion of hBN excitons and hybrid plasmons in hBN-WSe2 heterostructuresExternal link, npj 2D Mater. Appl. 8, 1 (2024).
- J. Krumland, S. Velja, and C. Cocchi, Quantum Dots in Transition Metal Dichalcogenides Induced by Atomic-Scale DeformationsExternal link, ACS Photonics 11, 586 (2024).
- S. Velja, J. Krumland, and C. Cocchi, Electronic properties of MoSe2 nanowrinklesExternal link, Nanoscale 16, 7134 (2024).
- J. Krumland and C. Cocchi, Ab Initio Modelling of Mixed-Dimensional Heterostructures: A Path ForwardExternal link, J. Phys. Chem. Lett. 15, 5350 (2024).
- J. Krumland and C. Cocchi, Conditions for electronic hybridization between transition-metal dichalcogenide monolayers and physisorbed carbon-conjugated moleculesExternal link, Electron. Struct. 3, 044003 (2021).
- J. Krumland and C. Cocchi, LayerPCM: An implicit scheme for dielectric screening from layered substratesExternal link, J. Chem. Phys. 154, 224114 (2021).
People involved:
- Dr. Surender Kumar
- Dr. M. Sufyan Ramzan
- Jiwon Kwon
- Stefan Velja
- Dr. Jannis Krumland (now at the University of Modena, Italy)
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Modeling Sustainable Materials for Clean Energy
Figure 2 – Sustainable materials for clean energy conversion and storage: Data driven discovery and characterization.
Image: Prof. Dr. Caterina CocchiWe model from first principles novel materials for clean energy technologies, including photovoltaics, catalysis, and batteries. Adopting state-of-the-art methods from high-throughput screening to many-body perturbation theory, we explore the structural, electronic, optical, and vibrational properties of a wide range of materials, from organic blends and crystals and inorganic semiconductors and oxides to halide perovskites and metal-organic frameworks. Target applications include solar cells, ultrabright electron sources, energy conversion and storage.
Key developments
High-throughput screening library “Automated ab-Initio Material Modelling and Data Analysis Toolkit (aim2dat)”: https://github.com/aim2dat/aim2datExternal link
Funded projects
- 2023 – 2027: „Grundlagen für Photovoltaik-Technologien der Zukunft (FuturePV)” funded by the Lower Saxony Ministry of Science and Culture
- 2022 – 2026: DFG project “Fundamental characterization and photoemission properties of multi-alkali antimonides for ultra-bright electron sources (FunPhotoSource)”
Relevant publications
- T. Reents, E. Kataev, D. Duarte-Ruiz, R. Wilks, R. Garcia-Diez, M. Bär, and C. Cocchi, Combinatorial Ab Initio Calculations and Core Spectroscopy Unravel the Electronic Structure of Nickel Cobalt Manganese OxideExternal link, Sci. Rep. 15, 5816 (2025).
- H.-D. Saßnick and C. Cocchi, Automated analysis of surface facets: The example of cesium tellurideExternal link, npj Comput. Mater. 10, 28 (2024).
- C. Cocchi, M. Guerrini, J. Krumland, N.T. Nguyen, and A. M. Valencia, Modeling the electronic structure of organic materials: A solid-state physicist's perspectiveExternal link, J. Phys.: Materials 6, 012001 (2022).
- A. M. Valencia, D. Bischof, S. Anhäuser, M. Zeplichal, A. Terfort, G. Witte, and C. Cocchi, Excitons in organic materials: Revisiting old concepts with new insightsExternal link, Electron. Struct. 5, 033003 (2023).
- C. Cocchi and H.-D. Saßnick, Ab Initio Quantum-Mechanical Predictions of Semiconducting Photocathode MaterialsExternal link, Micromachines 12, 1002 (2021).
People involved
- Dr. M. Sufyan Ramzan
- Dr. Ana M. Valencia (University of Oldenburg)
- Hilde Bellersen
- Khaoula El Asame
- Joshua Edzards
- Jiwon Kwon
- Ashby Jiji (University of Oldenburg)
- Julia Santana Andreo
- Richard Schier
- Dr. Holger-Dietrich Saßnick (now at the University of Montpellier, France)
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Nonlinear Optics
Figure 3 – Tw-dimensional electron spectroscopy from first principles.
Image: Prof. Dr. Caterina CocchiWe investigate the interactions between organic, inorganic, and hybrid materials and (intense) electromagnetic fields using time-dependent density-functional theory. Our primary interests are to understand how the characteristics of the material (composition, structure, etc.) and of the external field (duration, intensity, carrier frequency, polarization, delay etc.) influence nonlinear response.
Key developments
Two-dimensional electron spectroscopy from first principles: https://pubs.aip.org/aip/apr/article/11/1/011305/3105956External link
Funded projects
- 2025 – 2027: “Computational design of mixed-dimensional heterostructures for mid-gap state engineering and enhanced second-order optical nonlinearities” - project A8 in SFB 1375 “Nonlinear Optics at the Atomic scale (NOA)”
- 2024 – 2028: “Elektronen-Licht-Kontrolle (elLiKo)” financed by the Lower Saxony Ministry of Science and Culture
- 2024 – 2027: DFG project “Ab initio description of optical nonlinearities induced by impulsive broadband radiation (INPULS)”
Relevant publications
- J. Krumland, M. Guerrini, A. De Sio, C. Lienau, and C. Cocchi, Two-dimensional electronic spectroscopy from first principlesExternal link, Appl. Phys. Rev. 11, 011305 (2024).
- X. T. Nguyen, K. Winte, D. Timmer, Y. Rakita, D. Ceratti, S. Aharon, M. S. Ramzan, C. Cocchi, M. Lorke, F. Jahnke, D. Cahen, C. Lienau, and A. De Sio, Phonon-driven Intra-exciton Rabi Oscillations in CsPbBr3 Halide PerovskitesExternal link, Nat. Commun. 14, 1047 (2023).
- M. Jacobs, J. Krumland, and C. Cocchi, Laser-Controlled Charge Transfer in a Two-Dimensional Organic/Inorganic Optical Coherent NanojunctionExternal link, ACS Appl. Nano Mater. 5, 5187 (2022).
- C. Cocchi, D. Prezzi, A. Ruini, E. Molinari and C. A. Rozzi, Ab initio simulation of optical limiting: The case of metal-free phthalocyanineExternal link, Phys. Rev. Lett. 112, 198303 (2014).
People involved
- Dr. Michele Guerrini
- Dr. Anvar Khujakulov
- Dr. M. Sufyan Ramzan
- Mustapha Driouech
- Jannik Theile (University of Oldenburg)
- Dr. Jannis Krumland (now at the University of Modena, Italy)