Regensburg 2025 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 29: Poster II

HL 29.32: Poster

Dienstag, 18. März 2025, 18:00–20:00, P1

Probing the Band Splitting near the Γ Point in the van der Waals Magnetic Semiconductor CrSBr — •Kaiman Lin^1,2, Yi Li^1,3, Mahdi Ghorbani-Asl¹, Zdenek Sofer⁴, Stephan Winnerl¹, Artur Erbe^1,3, Arkady V. Krasheninnikov¹, Manfred Helm^1,3, Shengqiang Zhou¹, Yaping Dan², and Slawomir Prucnal¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — ²Shanghai Jiaotong University, Shanghai, China — ³TU- Dresden, Germany — ⁴University of Chemistry and Technology Prague, Czech Republic

As a van der Waals magnetic semiconductor, CrSBr has a direct bandgap of approximately 1.5 eV and undergoes an antiferromagnetic transition around 131 K [1]. In this study, the electronic band structure of CrSBr is investigated through comprehensive photoluminescence (PL) characterization [2]. We distinctly identify low-temperature optical transitions between two closely adjacent conduction-band states and two different valence-band states. The analysis of the PL data robustly reveals energy splittings, bandgaps, and excitonic transitions across different CrSBr thicknesses, ranging from monolayer to bulk. Temperature-dependent PL measurements shed light on the stability of band splitting below the Néel temperature, suggesting that magnons coupled with excitons are responsible for the symmetry breaking and the brightening of transitions from the secondary conduction band minimum (CBM2) to the global valence band maximum (VBM1). [1] N. P. Wilson, K. Lee, J. Cenker et al., Nat. Mater. 20, 1657 (2021). [2] K. Lin, et al. J. Phys. Chem. Lett. 15, 6010-6016 (2024).

Keywords: 2D materials; CrSBr; Band structure; Photoluminescence