Clear and transparent nanocrystals for infrared-responsive carrier transfer

Abstract

Infrared-light-induced carrier transfer is a key technology for ‘invisible’ optical devices for information communication systems and energy devices. However, clear and colourless photo-induced carrier transfer has not yet been demonstrated in the field of photochemistry, to the best of our knowledge. Here, we resolve this problem by employing short-wavelength-infrared (1400–4000 nm) localized surface plasmon resonance-induced electron injection from indium tin oxide nanocrystals to transparent metal oxides. The time-resolved infrared measurements visualize the dynamics of the carrier in this invisible system. Selective excitation of localized surface plasmon resonances causes hot electron injection with high efficiency (33%) and long-lived charge separation (~ 2–200 μs). We anticipate our study not only provides a breakthrough for plasmonic carrier transfer systems but may also stimulate the invention of state-of-the-art invisible optical devices.

Direct Quantification of Cu Vacancies and Spatial Localization of Surface Plasmon Resonances in Copper Phosphide Nanocrystals

“…9,10,11 This LSPR in the near infra-red is of interest for application in the field of invisible optics in communication or energy harvesting. 12,13 To unambiguously prove that the LSPR properties derive from the presence of Cu vacancies in the structure, a quantification of the Cu vacancies in the individual nanostructure is required. However, in copper chalcogenides, Cu + ions are highly mobile and therefore the sublattice of Cu + ions is highly disordered, which makes it difficult to visualize directly Cu vacancies with techniques such as scanning transmission electron microscopy (STEM).…”

“…The ability to image the spatial localization of the plasmonic resonances may then greatly assist in engineering these nanostructures for sensing and SERS. 13 The second main achievement of this work is thus the direct visualization of LSPRs in individual Cu 3-x P nanoplatelets by means of electron energy loss spectroscopy (EELS). Although the visualization of LSPRs is now routinely performed in individual metallic nanostructures such as Ag and Au 14,15,16 and can be used to verify predictions from various models (Drude and Mie models, or boundary element methods, etc.…”

Effect of Na‐Doping on Electron Decay Kinetics in SrTiO3 Photocatalyst

“…To obtain deeper understanding of the mechanism, it is essential to know how the behaviors of photoexcited electrons and holes are changed by doping. The transient absorption spectroscopy is a powerful tool to observe the photocarrier dynamics . In this work, we investigated the Na‐doping effect on photocarrier dynamics in SrTiO 3 by measuring transient absorption from visible to mid‐IR region.…”

Electrochemical and Photoelectrochemical Applications of Plasmonic Metal and Compound Nanoparticles

“…55 Electron injection from ITO NPs to SnO 2 based on PICS was also reported recently. 94 We also succeeded in colloidal synthesis of MoO 2 NPs in an organic solvent. 95 Those NPs, which show LSPR in the visible region, would be low-cost alternative to noble metal NPs in PICS applications.…”