Photo-modulated optical and electrical properties of graphene

Photo-modulation is a promising strategy for contactless and ultrafast control of optical and electrical properties of photoactive materials. Graphene is an attractive candidate material for photo-modulation due to its extraordinary physical properties and its relevance to a wide range of devices, from photodetectors to energy converters. In this review, we survey different strategies for photo-modulation of electrical and optical properties of graphene, including photogating, generation of hot carriers, and thermo-optical effects. We briefly discuss the role of nanophotonic strategies to maximize these effects and highlight promising fields for application of these techniques.

The anisotropic broadband surface plasmon polariton and hot carrier properties of borophene monolayer

Borophene monolayer with its intrinsic metallic and anisotropic band structures exhibits extraordinary electronic, optical, and transport properties. Especially, the high density of Dirac electrons enables promising applications for building low-loss broadband SPP devices. However, a systematic characterization of the surface plasmon polariton (SPP) properties and hot carriers generated from the inevitable SPP decay in borophene has not been reported so far. Most importantly, the mechanism for SPP losses remains obscurely quantified. In this work, from a fully first-principles perspective, we explicitly evaluate the main loss effects of SPP in borophene, including the Drude resistance, phonon-assisted intraband and direct interband electronic transitions. With this knowledge, we further calculate the frequency- and polarization-dependent SPP response of borophene, and evaluate some typical application-dependent figure of merits of SPP. On the other hand, we evaluate the generation and transport properties of plasmon-driven hot carriers in borophene, involving energy- and momentum-dependent carrier lifetimes and mean free paths, which provide deeper insight toward the transport of hot carriers at the nanoscale. These results indicate that borophene has promising applications in next-generation low-loss optoelectronic devices and photocatalytic reactors.

Optimizing the quasi-equilibrium state of hot carriers in all-inorganic lead halide perovskite nanocrystals through Mn doping: fundamental dynamics and device perspectives

Hot carrier (HC) cooling accounts for the significant energy loss in lead halide perovskites (LHPs) solar cells. Here, we study HC relaxation dynamics in Mn-doped LHP CsPbI3 nanocrystals (NCs), combining...

Directed Surface Plasmon Resonance for Hot Carrier Applications

The Special Issue, entitled Directed Surface Plasmon Resonance for Hot Carrier Applications, is a collection of four original articles centered around harnessing energetically “hot” carriers in tailored plasmonic materials for emergent applications in energy harvesting and sensing [...]

Plasmon-induced hot-hole generation and extraction at nano-heterointerfaces for photocatalysis

Localized surface plasmon resonance excitation presents tremendous opportunities for light-harvesting in the field of photocatalysis. Notably, the use of plasmon-generated hot carriers to drive chemical reactions offers the opportunity to control the selectivity of the reaction, unlike temperature-driven catalysis. There has been extensive development of photocatalysts based on plasmon-induced hot electron transfer. However, the equally important hole transfer process has been largely understudied mainly because of the ultrafast dynamics and shorter lifetime of holes compared to electrons. The electron and hole transport asymmetry to the catalytic site introduces additional challenges in extracting holes as oxidants for chemical adsorbents/reactants. This review provides a fundamental overview of plasmonic catalysis, emphasizing recent hot hole extraction and catalysis advancements by exploring different nano-heterointerfaces through which energetic holes can be localized to the catalytic sites. We also highlight some of the critical parameters which must be considered to address the limitations and introduce new possibilities to the field.