Narrow-Line Width Emission and Room Temperature Amplified Spontaneous Emission in Three-Dimensional Ge Halide Perovskites
Journal article, 2026
We report the structural and optoelectronic properties of lead-free CsGeI3 and CsGeBr3 perovskites, unveiling the critical role of local symmetry distortions in defining their emission properties. CsGeBr3 exhibits broad photoluminescence from self-trapped excitons, due to local octahedral distortion and a large distribution of the average bond lengths. On the contrary, by using temperature-dependent pair distribution function analysis and hybrid-functional molecular dynamics simulations, we demonstrate that CsGeI3 adopts a monoclinic local structure responsible for its narrow near-infrared (NIR) emission (similar to 745 nm, FWHM approximate to 110 meV at room temperature), the narrowest reported for Ge-based perovskites and in line with tin iodide perovskites. Notably, the high level of structural order also supports the achievement of amplified spontaneous emission (ASE) at room temperature with an exceptionally low threshold (75 mu J/cm2), positioning it as a promising candidate for lead-free NIR light-emitting and laser applications.
Author
Marta Morana
University of Florence
Andera Olivati
Istituto Italiano di Tecnologia
Marco Moroni
Universita degli studi di Pavia
Giulia Folpini
National Research Council of Italy (CNR)
Istituto Italiano di Tecnologia
Mehmet Baskurt
Chalmers, Physics, Condensed Matter and Materials Theory
Margherita Garbaccio
Universita degli studi di Pavia
Annamaria Petrozza
Istituto Italiano di Tecnologia
Francesco Ambrosio
University of Basilicata
Julia Wiktor
Chalmers, Physics, Condensed Matter and Materials Theory
Lorenzo Malavasi
Universita degli studi di Pavia
Chemistry of Materials
0897-4756 (ISSN) 1520-5002 (eISSN)
Vol. 38 6446-6455Harnessing Localized Charges for Advancing Polar Materials Engineering (POLARISE)
European Commission (EC) (EC/HE/101162195), 2025-01-01 -- 2029-12-31.
Ab Initio Description of Complete Semiconductor Devices
Swedish Foundation for Strategic Research (SSF) (FFL21-0129), 2022-08-01 -- 2027-12-31.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Condensed Matter Physics
DOI
10.1021/acs.chemmater.6c00408
Related datasets
Supporting Information [dataset]
DOI: 10.1021/acs.chemmater.6c00408. URI: https://pubs.acs.org/doi/10.1021/acs.chemmater.6c00408.