Dynamic control of X-ray core-exciton resonances by Coulomb screening in photoexcited semiconductors
Year: 2025
Type: article
Abstract: Excitonics is an emerging field focused on exploiting and manipulating excitons generated through light-matter interactions. Advancing the field into X-ray excitonics requires precise energy and time control of core-exciton resonances, enabling non-linear X-ray phenomena such as element-specific X-ray transient gratings, and advancing material characterization. To achieve these objectives, it is essential to comprehend the role of many-body effects governing core-exciton dynamics. In this work, we address this challenge by combining experiments with an ab initio approach specifically developed to interpret pump-probe excitations. Applied to the prototypical wide-bandgap semiconductor ZnO, first-principles calculations reproduce experimental results and unveil how the density and distribution of photoexcited carriers dynamically tune Coulomb screening, thereby controlling core-exciton binding energies, while Pauli blocking remains negligible. These insights inform a method for dynamically controlling core-exciton resonances at absorption edges, achieving either a uniform spectral blue shift caused by thermalized carrier distributions on picosecond timescales, or distinct blue shifts for individual resonances, driven by time-dependent carrier distributions on femtosecond timescales.
Source: Communications Materials
Authors: Thomas C. Rossi, Lu Qiao, Conner P. Dykstra, Ronaldo Rodrigues Pela, Richard Gnewkow, Rachel F. Wallick, John H. Burke, Erin Nicholas, Anne Marie March, Gilles Doumy, D. Bruce Buchholz, Christiane Deparis, Jesús Zúñiga-Pérez, Michael Weise, Klaus Ellmer, Mattis Fondell, Claudia Draxl, Renske M. van der Veen
Institutions: Helmholtz-Zentrum Berlin für Materialien und Energie, Humboldt-Universität zu Berlin, University of Illinois Urbana-Champaign, Zuse Institute Berlin, Technische Universität Berlin, Argonne National Laboratory, Northwestern University, Centre National de la Recherche Scientifique, Université Côte d'Azur, Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications, National University of Singapore, Nanyang Technological University, Sorbonne Université, UMI MajuLab, Optotransmitter-Umweltschutz-Technologie e.V.
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,690
Funders: National Science Foundation, U.S. Department of Defense, U.S. Department of Energy, Alexander von Humboldt-Stiftung, Northwestern University, Deutsche Forschungsgemeinschaft, Office of Science, Helmholtz-Zentrum Berlin für Materialien und Energie, Materials Research Science and Engineering Center, Harvard University, Division of Materials Research, Division of Electrical, Communications and Cyber Systems, Basic Energy Sciences, Argonne National Laboratory
Awards: G102163711, G107546177, NNCI: Soft Hybrid Nanotechnology Experimental (SHyNE) Resource, G1286251239, G1313983767, G1664757510, G1829968774, G2233802770, G2287611682, G2343375527, G262962599, G3010471893, G3075337988, G3203750490, G3479632140, G3589692066, PROBING ULTRAFAST CHARGE TRANSFER DYNAMICS IN HETEROSTRUCTURED NANOMATERIALS, G373498054, G3954585026, G4157079217, G426311843, Northwestern University Materials Research Science and Engineering Center, Vielteilchenwechselwirkungen in zweidimensionalen HalogenidPerowskiten: ExzitonElektron Zustände und ElektronPhonon Kopplung, G4958141111, G498139845, G513797252, G5387317844, G6540817556, G6848031779, SFB 951: Hybrid Inorganic/Organic Systems (HIOS) for OptoElectronics, G6918803902, G7583137537, CATALYTIC REACTION INTERMEDIATES REVEALED WITH FEMTOSECOND M-EDGE XANES, G969889393, G993149817
OpenAlex ID: W4413350341