Ultranarrow Photoluminescence from Individual Graphene Nanoribbons Showing Single-Photon Emission

Journal article

Graphene nanoribbons (GNRs) combine the remarkable optical and electronic properties of graphene with the presence of a tunable band gap, making them promising for optoelectronic applications. Here, we investigate the excitonic properties of individual cove-edge GNRs through microphotoluminescence (micro-PL) spectroscopy. We observe ultranarrow emission lines with full width at half-maximum as low as 24 μeV, demonstrating a reduction of inhomogeneous broadening by 3 orders of magnitude compared to GNR ensembles. Temperature-dependent PL reveals phonon-mediated broadening mechanisms, with electron–phonon coupling parameters in agreement with ensemble studies but with dramatically reduced line widths. Time-resolved PL suggests long-lived excitonic states, while spectral diffusion analysis demonstrates stable emission energies, highlighting the exceptional quality of these GNRs as single-photon emitters. The absence of intensity blinking and low Mandel parameters further support the robustness of the emission properties. Our findings establish cove-edge GNRs as promising candidates for quantum light sources and nanoscale optoelectronic applications.

Authors: Sturdza, BK; Pawbake, A; Faugeras, C; Niu, W; Ma, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Nano Letters
• Volume: 26
• Issue: 13
• Pages: 4432-4438
• Publication date: 2026-03-27
• Acceptance date: 2026-03-13
• DOI: 10.1021/acs.nanolett.6c00287
• EISSN: 1530-6992
• ISSN: 1530-6984
• Language: English
• Keywords: time-resolved PL; spectral diffusion; photoluminescence; zero-phonon line; single-photon emission; electron−phonon coupling; graphene nanoribbons