Low-dimensional materials have left a mark on modern materials science,creating new opportunities for next-generation optoelectronic applications.Integrating disparate nanoscale building blocks into heterostructures o...Low-dimensional materials have left a mark on modern materials science,creating new opportunities for next-generation optoelectronic applications.Integrating disparate nanoscale building blocks into heterostructures offers the possibility of combining the advantageous features of individual components and exploring the properties arising from their interactions and atomic-scale proximity.The sensitization of graphene using semiconductors provides a highly promising platform for advancing optoelectronic applications through various hybrid systems.A critical aspect of achieving superior performance lies in understanding and controlling the fate of photogenerated charge carriers,including generation,transfer,separation,and recombination.Here,we review recent advances in understanding charge carrier dynamics in graphene-semiconductor heterostructures by ultrafast laser spectroscopies.First,we present a comprehensive overview of graphene-based heterostructures and their state-of-the-art optoelectronic applications.This is succeeded by an introduction to the theoretical frameworks that elucidate the fundamental principles and determinants influencing charge transfer and energy transfer—two critical interfacial processes that are vital for both fundamental research and device performance.We then outline recent efforts aimed at investigating ultrafast charge/energy flow in graphene-semiconductor heterostructures,focusing on illustrating the trajectories,directions,and mechanisms of transfer and recombination processes.Subsequently,we discuss effective control knobs that allow fine-tuning of these processes.Finally,we address the challenges and prospects for further investigation in this field.展开更多
Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical rea...Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical reactivity,fluorescence,phase behavior,and charge transport.Here,we explore the effect of resonant cavity-phonon coupling on the transient photoconductivity in a hybrid organic-inorganic perovskite.To this end,we measure the ultrafast photoconductivity response of perovskite in a tunable Fabry–Pérot terahertz cavity,designed to be transparent for optical excitation.The terahertz-cavity field-phonon interaction causes apparent Rabi splitting between the perovskite phonon mode and the cavity mode.We explore whether the cavity-phonon interaction affects the material’s electron-phonon interaction by determining the charge-carrier mobility through photoconductivity.Despite the apparent hybridization of cavity and phonon modes,we show that the perovskite properties in both ground(phonon response)and excited(photoconductive response)states remain unaffected by the tunable light-matter interaction.Yet the response of the integral perovskite-terahertz optical cavity system depends critically on the interaction strength of the cavity with the phonon:the transient terahertz response to optical excitation can be increased up to threefold by tuning the cavity-perovskite interaction strength.These results enable tunable switches and frequency-controlled induced transparency devices.展开更多
Heterogeneous ice nucleation(HIN)on foreign surfaces plays a crucial role across a wide range of environmental and biological processes,and control of HIN is highly desirable.Functionalizing surfaces to control HIN po...Heterogeneous ice nucleation(HIN)on foreign surfaces plays a crucial role across a wide range of environmental and biological processes,and control of HIN is highly desirable.Functionalizing surfaces to control HIN poses interesting scientific challenges and holds great potential for technological impact.Here,we combine the ice nucleation tuning capability of polyelectrolytes withmussel-inspired adhesives to obtain robust surface functionalization with HIN control.展开更多
基金funding from European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no.804349(ERC StG CUHL)FLAG-ERA grant ENPHOCAL,by MICIN with no.PCI2021-122101-2A(Spain)supported by the Severo Ochoa program from Spanish MINECO grant no.SEV-2017-0706.
文摘Low-dimensional materials have left a mark on modern materials science,creating new opportunities for next-generation optoelectronic applications.Integrating disparate nanoscale building blocks into heterostructures offers the possibility of combining the advantageous features of individual components and exploring the properties arising from their interactions and atomic-scale proximity.The sensitization of graphene using semiconductors provides a highly promising platform for advancing optoelectronic applications through various hybrid systems.A critical aspect of achieving superior performance lies in understanding and controlling the fate of photogenerated charge carriers,including generation,transfer,separation,and recombination.Here,we review recent advances in understanding charge carrier dynamics in graphene-semiconductor heterostructures by ultrafast laser spectroscopies.First,we present a comprehensive overview of graphene-based heterostructures and their state-of-the-art optoelectronic applications.This is succeeded by an introduction to the theoretical frameworks that elucidate the fundamental principles and determinants influencing charge transfer and energy transfer—two critical interfacial processes that are vital for both fundamental research and device performance.We then outline recent efforts aimed at investigating ultrafast charge/energy flow in graphene-semiconductor heterostructures,focusing on illustrating the trajectories,directions,and mechanisms of transfer and recombination processes.Subsequently,we discuss effective control knobs that allow fine-tuning of these processes.Finally,we address the challenges and prospects for further investigation in this field.
基金This work has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant No 811284.
文摘Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical reactivity,fluorescence,phase behavior,and charge transport.Here,we explore the effect of resonant cavity-phonon coupling on the transient photoconductivity in a hybrid organic-inorganic perovskite.To this end,we measure the ultrafast photoconductivity response of perovskite in a tunable Fabry–Pérot terahertz cavity,designed to be transparent for optical excitation.The terahertz-cavity field-phonon interaction causes apparent Rabi splitting between the perovskite phonon mode and the cavity mode.We explore whether the cavity-phonon interaction affects the material’s electron-phonon interaction by determining the charge-carrier mobility through photoconductivity.Despite the apparent hybridization of cavity and phonon modes,we show that the perovskite properties in both ground(phonon response)and excited(photoconductive response)states remain unaffected by the tunable light-matter interaction.Yet the response of the integral perovskite-terahertz optical cavity system depends critically on the interaction strength of the cavity with the phonon:the transient terahertz response to optical excitation can be increased up to threefold by tuning the cavity-perovskite interaction strength.These results enable tunable switches and frequency-controlled induced transparency devices.
文摘Heterogeneous ice nucleation(HIN)on foreign surfaces plays a crucial role across a wide range of environmental and biological processes,and control of HIN is highly desirable.Functionalizing surfaces to control HIN poses interesting scientific challenges and holds great potential for technological impact.Here,we combine the ice nucleation tuning capability of polyelectrolytes withmussel-inspired adhesives to obtain robust surface functionalization with HIN control.
