When Cubic is Not Isotropic: Phonon–Exciton Decoupling in CuInSnS4 Single Crystals
Linke LK, Tomm Y, Liu X, Gurieva G, Többens DM, Adams P, Calame M, Crisp R, Boland J, Kavanagh S, Schorr S, Dimitrievska M (2026)
Publication Type: Journal article
Publication year: 2026
Journal
DOI: 10.1002/adom.71392
Abstract
Atomic-scale disorder can create hidden optical anisotropy even in crystals that are structurally cubic on average. Here, we show that (Formula presented.) single crystals host locally symmetry-broken environments arising from intrinsic In/Sn cation disorder, which affect vibrational and excitonic properties in markedly different ways. Combining polarization- and temperature-dependent Raman spectroscopy, infrared near-field microscopy, steady-state and time-resolved photoluminescence, and first-principles calculations, we find that phonons remain largely symmetry-averaged and locally homogeneous on the nanoscale. In contrast, photoluminescence reveals a lower-energy band-tail emission with pronounced polarization anisotropy following a well-defined angular symmetry, highlighting the strong sensitivity of excitonic states to local symmetry breaking. This phonon–exciton decoupling reveals that intrinsic disorder can localize excitons while preserving vibrational coherence and dielectric homogeneity, thereby opening new opportunities for polarization-sensitive light sources, anisotropic photodetectors, and exciton-based optical functionalities even in nominally cubic multinary semiconductors.
Authors with CRIS profile
Involved external institutions
Helmholtz-Zentrum Berlin für Materialien und Energie (HZB)
Germany (DE)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
University of Manchester
United Kingdom (GB)
University of Zurich / Universität Zürich (UZH)
Switzerland (CH)
University of Cambridge
United Kingdom (GB)
Germany (DE)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
University of Manchester
United Kingdom (GB)
University of Zurich / Universität Zürich (UZH)
Switzerland (CH)
University of Cambridge
United Kingdom (GB)
How to cite
APA:
Linke, L.K., Tomm, Y., Liu, X., Gurieva, G., Többens, D.M., Adams, P.,... Dimitrievska, M. (2026). When Cubic is Not Isotropic: Phonon–Exciton Decoupling in CuInSnS4 Single Crystals. Advanced Optical Materials. https://doi.org/10.1002/adom.71392
MLA:
Linke, Lara Kim, et al. "When Cubic is Not Isotropic: Phonon–Exciton Decoupling in CuInSnS4 Single Crystals." Advanced Optical Materials (2026).
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