Observation of Considerable Upconversion Enhancement Induced by Cu_2–xS Plasmon Nanoparticles

Abstract

Localized surface plasmon resonances (LSPRs) are achieved in heavily doped semiconductor nanoparticles (NPs) with appreciable free carrier concentrations. In this paper, we present the photonic, electric, and photoelectric properties of plasmonic Cu2-xS NPs/films and the utilization of LSPRs generated from semiconductor NPs as near-infrared antennas to enhance the upconversion luminescence (UCL) of NaYF4:Yb(3+),Er(3+) NPs. Our results suggest that the LSPRs in Cu2-xS NPs originate from ligand-confined carriers and that a heat treatment resulted in the decomposition of ligands and oxidation of Cu2-xS NPs; these effects led to a decrease of the Cu(2+)/Cu(+) ratio, which in turn resulted in the broadening, decrease in intensity, and red-shift of the LSPRs. In the presence of a MoO3 spacer, the UCL intensity of NaYF4:Yb(3+),Er(3+) NPs was substantially improved and exhibited extraordinary power-dependent behavior because of the energy band structure of the Cu2-xS semiconductor. These findings provide insights into the nature of LSPR in semiconductors and their interaction with nearby emitters and highlight the possible application of LSPR in photonic and photoelectric devices.

Photon Upconversion Kinetic Nanosystems and Their Optical Response

“…In many applications, the brightness of UCNPs is not the limiting factor, e.g., for laser scanning microscopy, whereas the long lifetime of Ln 3 + ions remains an obstacle, like for fast high‐quality imaging, which necessitates optical or data‐postprocess techniques to eliminate the bleeding effect in imaging . Tailoring the lifetime of Ln 3 + ions may be achieved by integrating plasmonic effects of nanosized noble metals and plasmonic semiconductor nanomaterials (ii)Better integration of UCNPs with other materials.…”

“…[135][136][137][138] Tailoring the lifetime of Ln 3+ ions may be achieved by integrating plasmonic effects of nanosized noble metals and plasmonic semiconductor nanomaterials. [200][201][202][203][204][205] (ii) Better integration of UCNPs with other materials. The motivation of this task includes: (a) increasing the efficiency of photon upconversion and extending the excitation spectrum by employing antenna effects; (b) constructing novel heterostructures with other attractive properties by making use of their complementary advantages; and (c) facilitating energy transfer from UCNPs to subsequent molecules to improve the performance of NIR-triggered photoactivation and bioassays.…”

Near‐Infrared‐Plasmonic Energy Upconversion in a Nonmetallic Heterostructure for Efficient H2 Evolution from Ammonia Borane

“…LSPR band and intensity of the semiconductor can be easily controlled via adjusting the stoichiometric ratios, vacancy, or dopant concentrations, as well as phase structures 21, 22, 23. Among the plasmonic semiconductor nanostructures, tungsten oxide NWs, W 18 O 49 , made via a facile solvothermal method, possess intense LSPR band across the visible and NIR regions due to abundant oxygen vacancies on their surface 24, 25, 26.…”

Structure‐Selective Cation Exchange in the Synthesis of Zincblende MnS and CoS Nanocrystals

“…[25] (See the Supporting Information (SI) for complete experimental details.) [25] (See the Supporting Information (SI) for complete experimental details.)…”

“…[25] (See the Supporting Information (SI) for complete experimental details.) [26] Consistent with previous reports of colloidally synthesized copper sulfide nanoparticles, [17,25,27] as mall amount of the lower-temperature rhombohedral form of digenite is also present. [26] Consistent with previous reports of colloidally synthesized copper sulfide nanoparticles, [17,25,27] as mall amount of the lower-temperature rhombohedral form of digenite is also present.…”