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RESEARCH PRODUCT
Experimental Observation of Strong Exciton Effects in Graphene Nanoribbons
Fugui XuCharusheela RamananMathias KläuiYiyong MaiPengfei ZhangDavid BeljonneHai I. WangSilvio OsellaAlexander TriesAlexander Triessubject
Materials scienceLetter530 PhysicsBand gapExcitonExciton binding energyBinding energyFOS: Physical sciencesPhysics::OpticsBioengineering02 engineering and technologyElectronNanomaterialsCondensed Matter::Materials ScienceMesoscale and Nanoscale Physics (cond-mat.mes-hall)General Materials ScienceExciton formationCondensed Matter - Mesoscale and Nanoscale Physicsbusiness.industryMechanical EngineeringGraphene nanoribbonsGeneral Chemistry530 Physik021001 nanoscience & nanotechnologyCondensed Matter PhysicsTHz spectroscopyOptoelectronicsCharge carrierExcitons0210 nano-technologybusinessUltrashort pulseGraphene nanoribbonsOptics (physics.optics)Physics - Opticsdescription
Graphene nanoribbons (GNRs) with atomically precise width and edge structures are a promising class of nanomaterials for optoelectronics, thanks to their semiconducting nature and high mobility of charge carriers. Understanding the fundamental static optical properties and ultrafast dynamics of charge carrier generation in GNRs is essential for optoelectronic applications. Combining THz spectroscopy and theoretical calculations, we report a strong exciton effect with binding energy up to 700 meV in liquid-phase-dispersed GNRs with a width of 1.7 nm and an optical bandgap of 1.6 eV, illustrating the intrinsically strong Coulomb interactions between photogenerated electrons and holes. By tracking the exciton dynamics, we reveal an ultrafast formation of excitons in GNRs with a long lifetime over 100 ps. Our results not only reveal fundamental aspects of excitons in GNRs (gigantic binding energy and ultrafast exciton formation etc.), but also highlight promising properties of GNRs for optoelectronic devices.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-11-11 |