Luminescence constitutes a unique source of insight into hot carrier processes in metals,including those in plasmonic nanostructures used for sensing and energy applications.However,being weak in nature,metal luminesc...Luminescence constitutes a unique source of insight into hot carrier processes in metals,including those in plasmonic nanostructures used for sensing and energy applications.However,being weak in nature,metal luminescence remains poorly understood,its microscopic origin strongly debated,and its potential for unraveling nanoscale carrier dynamics largely unexploited.Here,we reveal quantum-mechanical effects in the luminescence emanating from thin monocrystalline gold flakes.Specifically,we present experimental evidence,supported by first-principles simulations,to demonstrate its photoluminescence origin(i.e.,radiative emission from electron/hole recombination)when exciting in the interband regime.Our model allows us to identify changes to the measured gold luminescence due to quantum-mechanical effects as the gold film thickness is reduced.Excitingly,such effects are observable in the luminescence signal from flakes up to 40 nm in thickness,associated with the out-of-plane discreteness of the electronic band structure near the Fermi level.We qualitatively reproduce the observations with first-principles modeling,thus establishing a unified description of luminescence in gold monocrystalline flakes and enabling its widespread application as a probe of carrier dynamics and light-matter interactions in this material.Our study paves the way for future explorations of hot carriers and charge-transfer dynamics in a multitude of material systems.展开更多
基金ARB and FK acknowledge the support of SNSF Eccellenza Grant PCEGP2-194181ARB acknowledges SNSF Swiss Postdoctoral Fellowship TMPFP2_217040 and thanks Valeria Vento and Christophe Galland for the use of a commercial monocrystalline 200 nm gold sample,and Franky Esteban Bedoya Lora for the use of the Ocean Optics spectrometer.+5 种基金ARE,FI and FJGA acknowledge funding from the European Research Council(Advanced Grant No.789104-eNANO)the Spanish MICINN(PID2020-112625 GB-I00 and Severo Ochoa CEX2019-000910-S)the Catalan CERCA Program,and Fundacios Cellex and Mir-Puig.JDC is a Sapere Aude research leader supported by VILLUM FONDEN(Grant no.16498)Independent Research Fund Denmark(Grant no.0165-00051B)The Center for Polariton-driven Light-Matter Interactions(POLIMA)is funded by the Danish National Research Foundation(Project No.DNRF165)First-principles calculations were carried out at the Center for Computational Innovations at Rensselaer Polytechnic Institute.
文摘Luminescence constitutes a unique source of insight into hot carrier processes in metals,including those in plasmonic nanostructures used for sensing and energy applications.However,being weak in nature,metal luminescence remains poorly understood,its microscopic origin strongly debated,and its potential for unraveling nanoscale carrier dynamics largely unexploited.Here,we reveal quantum-mechanical effects in the luminescence emanating from thin monocrystalline gold flakes.Specifically,we present experimental evidence,supported by first-principles simulations,to demonstrate its photoluminescence origin(i.e.,radiative emission from electron/hole recombination)when exciting in the interband regime.Our model allows us to identify changes to the measured gold luminescence due to quantum-mechanical effects as the gold film thickness is reduced.Excitingly,such effects are observable in the luminescence signal from flakes up to 40 nm in thickness,associated with the out-of-plane discreteness of the electronic band structure near the Fermi level.We qualitatively reproduce the observations with first-principles modeling,thus establishing a unified description of luminescence in gold monocrystalline flakes and enabling its widespread application as a probe of carrier dynamics and light-matter interactions in this material.Our study paves the way for future explorations of hot carriers and charge-transfer dynamics in a multitude of material systems.
