We investigate the electronic structure of complex materials for optoelectronic and photovoltaic applications, for energy conversion and storage, as well as for electron sources. Our current activities focus on halide perovskites, ternary oxides, metal-organic frameworks, and multi-alkali antimonides and tellurides.

To discover and characterize these materials, we employ high-throughput screening interfaced with density-functional theory. Spectroscopic properties are investigated using time-dependent density-functional theory and many-body perturbation theory. 

For review, see 

• L. Schmidt-Mende, et al., C. Cocchi, et al., Roadmap on Organic-inorganic hybrid perovskite semiconductors and devices, APL Materials, 9, 109202 (2021). 
• C. Cocchi and H.-D. Saßnick, Ab initio quantum-mechanical predictions of semiconducting photocathode materials, Micromachines 12, 1002 (2021).

Funded Projects 

• GLIMPSE (DFG Priority Program 2196)
• SMART
• operaXX in BMBF-cluster AQua
• FunPhotoSource (DFG)

Relevant Publications

• F. Machado Ferreira De Araujo, D. Duarte-Ruiz, H.-D. Saßnick, M. C. Genzmann, T. Huthwelker, and C. Cocchi, Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs, Inorg. Chem., 62,  4238 (2023).
• 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, A. De Sio, Phonon-driven intra-exciton Rabi oscillations in CsPbBr₃ halide  perovskites, Nat. Commun., 14, 1047 (2023).
• A. Chmielewski, Z. Deng, D. Duarte-Ruiz, L. Miao, P. Moradifar, Y. Zhang, A. Mauze, C. Cocchi, W. Windl, N. Alem, Al coordination and Ga interstitial stability in a β-(Al_0.2Ga_0.8)₂O₃ thin film, ACS Applied Nano Materials, 15, 8601 (2023).
• R. Schier, H.-D. Saßnick, and C. Cocchi, Stability and electronic properties of CsK₂Sb surface facets, Phys. Rev. Materials 6, 125001 (2022).
• D. Duarte-Ruiz and C. Cocchi, First-principles core spectroscopy of LiCoO₂ and CoO₂, J. Phys. Chem. C 126, 10949 (2022).
• H.-D. Saßnick and C. Cocchi, Exploring the Cs-Te phase space via high-throughput density-functional theory calculations beyond the generalized-gradient approximation, J. Chem. Phys., 156, 104108 (2022).
• G. Procida, R. Schier, A. M. Valencia, and C. Cocchi, First-principles analysis of the optical properties of lead halide perovskite solution precursors, Phys. Chem. Chem. Phys. 23, 21087 (2021). 
• R. Schier, A. Conesa Rodriguez, A. M. Valencia, and C. Cocchi, Formation of lead halide perovskite precursors in solution: Insight from electronic-structure theory, Phys. Stat. Solidi B 258, 2100359  (2021).
• H.-D. Saßnick and C. Cocchi, Electronic Structure of Cesium-based Photocathode Materials from Density Functional Theory: Performance of PBE, SCAN, and HSE06 functionals, Electronic Stucture, 3, 027001 (2021).
• R. Amador, H.-D. Saßnick, and C. Cocchi, Electronic structure and optical properties of Na₂KSb and NaK₂Sb from first-principles many-body theory, J. Phys.: Condens. Matter 33, 365502 (2021).
• A. M. Valencia, O. Shargaieva, R. Schier, E. Unger, and C. Cocchi, Optical Fingerprints of Polynuclear Complexes in Lead Halide Perovskite Precursor Solutions, J. Phys. Chem. Lett. 12, 2299 (2021).
• C. Cocchi, X-ray absorption fingerprints from Cs atoms in Cs₃Sb, Physica Status Solidi – RRL 4, 2000194 (2020).
• C. Cocchi, S. Mistry, M. Schmeißer, R. Amador, J. Kühn, and T. Kamps, Electronic structure and core electron fingerprints of caesium-based multi-alkali antimonides for ultra-bright electron sources, Scientific Reports 9, 18276 (2019).
• C. Cocchi, S. Mistry, M. Schmeißer, J. Kühn, and T, Kamps, First-principles many-body study of the electronic and optical properties of CsK₂Sb, a semiconducting material for ultra-bright electron sources, J. Phys.: Condens. Matter 31, 014002 (2018).