Excitonics,an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law.Currently,the development of excitonic devices,where exciton flow is cont...Excitonics,an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law.Currently,the development of excitonic devices,where exciton flow is controlled,is mainly focused on electric-field modulation or exciton polaritons in high-Q cavities.Here,we show an alloptical strategy to manipulate the exciton flow in a binary colloidal quantum well complex through mediation of the Förster resonance energy transfer(FRET)by stimulated emission.In the spontaneous emission regime,FRET naturally occurs between a donor and an acceptor.In contrast,upon stronger excitation,the ultrafast consumption of excitons by stimulated emission effectively engineers the excitonic flow from the donors to the acceptors.Specifically,the acceptors’stimulated emission significantly accelerates the exciton flow,while the donors’stimulated emission almost stops this process.On this basis,a FRET-coupled rate equation model is derived to understand the controllable exciton flow using the density of the excited donors and the unexcited acceptors.The results will provide an effective alloptical route for realizing excitonic devices under room temperature operation.展开更多
Optical barcodes have demonstrated a great potential in multiplexed bioassays and cell tracking for their distinctive spectral fingerprints.The vast majority of optical barcodes were designed to identify a specific ta...Optical barcodes have demonstrated a great potential in multiplexed bioassays and cell tracking for their distinctive spectral fingerprints.The vast majority of optical barcodes were designed to identify a specific target by fluorescence emission spectra,without being able to characterize dynamic changes in response to analytes through time.To overcome these limitations,the concept of the bioresponsive dynamic photonic barcode was proposed by exploiting interfacial energy transfer between a microdroplet cavity and binding molecules.Whispering-gallery modes resulting from cavity-enhanced energy transfer were therefore converted into photonic barcodes to identify binding activities,in which more than trillions of distinctive barcodes could be generated by a single droplet.Dynamic spectral barcoding was achieved by a significant improvement in terms of signal-to-noise ratio upon binding to target molecules.Theoretical studies and experiments were conducted to elucidate the effect of different cavity sizes and analyte concentrations.Timeresolved fluorescence lifetime was implemented to investigate the role of radiative and non-radiative energy transfer.Finally,microdroplet photonic barcodes were employed in biodetection to exhibit great potential in fulfilling biomedical applications.展开更多
基金financial support through the AcRF Tier1 grant(MOE2019-T1-002-087)the Singapore National Research Foundation for financial support under the Program of NRF-NRFI-2016-08financial support from the TUBA.
文摘Excitonics,an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law.Currently,the development of excitonic devices,where exciton flow is controlled,is mainly focused on electric-field modulation or exciton polaritons in high-Q cavities.Here,we show an alloptical strategy to manipulate the exciton flow in a binary colloidal quantum well complex through mediation of the Förster resonance energy transfer(FRET)by stimulated emission.In the spontaneous emission regime,FRET naturally occurs between a donor and an acceptor.In contrast,upon stronger excitation,the ultrafast consumption of excitons by stimulated emission effectively engineers the excitonic flow from the donors to the acceptors.Specifically,the acceptors’stimulated emission significantly accelerates the exciton flow,while the donors’stimulated emission almost stops this process.On this basis,a FRET-coupled rate equation model is derived to understand the controllable exciton flow using the density of the excited donors and the unexcited acceptors.The results will provide an effective alloptical route for realizing excitonic devices under room temperature operation.
基金We would like to thank the Centre of Bio-Devices and Bioinformatics and CNRS International—Nanyang Technological University-Thales Research Alliance(CINTRA)for lab supportWe would also like to thank NTU for the startup grant(SUG-M4082308.040).
文摘Optical barcodes have demonstrated a great potential in multiplexed bioassays and cell tracking for their distinctive spectral fingerprints.The vast majority of optical barcodes were designed to identify a specific target by fluorescence emission spectra,without being able to characterize dynamic changes in response to analytes through time.To overcome these limitations,the concept of the bioresponsive dynamic photonic barcode was proposed by exploiting interfacial energy transfer between a microdroplet cavity and binding molecules.Whispering-gallery modes resulting from cavity-enhanced energy transfer were therefore converted into photonic barcodes to identify binding activities,in which more than trillions of distinctive barcodes could be generated by a single droplet.Dynamic spectral barcoding was achieved by a significant improvement in terms of signal-to-noise ratio upon binding to target molecules.Theoretical studies and experiments were conducted to elucidate the effect of different cavity sizes and analyte concentrations.Timeresolved fluorescence lifetime was implemented to investigate the role of radiative and non-radiative energy transfer.Finally,microdroplet photonic barcodes were employed in biodetection to exhibit great potential in fulfilling biomedical applications.
