Plasmonic Copper Sulfide-Based Materials: A Brief Introduction to Their Synthesis, Doping, Alloying, and Applications

Abstract

Plasmonic copper sulfide-based colloidal nanocrystals (NCs) have attracted considerable attention due to their unique and versatile optical and electronic properties. In this Feature Article, we first introduce the optical properties of these p-type semiconductor nanostructures, particularly localized surface plasmon resonance (LSPR). We then discuss nanostructures of copper sulfides [CuS and Cu 2−x S, (0 ≤ x < 1)] with different crystal structures and optical properties. In addition to the synthesis and transformation between these copper sulfide phases, we review their doping or alloying with extrinsic cations, which can produce homogeneous alloy nanostructures, new crystal phases, and multidomain (e.g., core−shell or dimer) NCs. In general, divalent cations (e.g., Zn, Hg, Cd) do not form a homogeneous phase upon incorporation into copper sulfide NCs, but trivalent and tetravalent cations (e.g., In, Sn, Ga) can do so. Filling of the Cu vacancies responsible for p-type doping results in red-shifting and damping of the LSPR upon incorporation of extrinsic elements. Finally, we present some emerging applications of copper sulfide-based nanomaterials.

Electrochemical Fingerprint of CuS-Hexagonal Chemistry from (Bis(N-1,4-Phenyl-N-(4-Morpholinedithiocarbamato) Copper(II) Complexes) as Photon Absorber in Quantum-Dot/Dye-Sensitised Solar Cells

“…Copper monosulfide (CuS) has distinguished itself among metal sulfides owing to its different band gap and various morphologies. This makes CuS a hot-spot semiconductor material with great potential in the field of photocatalytic and photovoltaic applications [18][19][20][21][22][23][24][25][26]. Hexagonal covellite-CuS with a bandgap of ∼2 eV and a p-type-enhances absorber abilities to cover the entire solar spectrum [18,19].…”

“…This makes CuS a hot-spot semiconductor material with great potential in the field of photocatalytic and photovoltaic applications [18][19][20][21][22][23][24][25][26]. Hexagonal covellite-CuS with a bandgap of ∼2 eV and a p-type-enhances absorber abilities to cover the entire solar spectrum [18,19]. Furthermore, CuS absorbs the infrared area through plasmonic absorption emanating from copper valencies due to a high concentration of charge carriers [20,26,27].…”

Glycosylated Copper Sulfide Nanocrystals for Targeted Photokilling of Bacteria in the Near‐Infrared II Window

“…Although new materials are continuously developed for either PTT or PDT in the NIR II window, [15,16] materials with a single component for simultaneous PTT and PDT at a single wavelength are still rare. [22] In addition to the high photothermal conversion efficiency, [17][18][19][20][21] light-induced copper ion release from Cu 2−x S NCs can initiate generation of hydroxyl radicals for efficient killing of cells. [11,[17][18][19][20][21] The high concentration of copper vacancies in the Cu 2−x S NCs gives rise to a strong localized plasmonic resonance, resulting in strong light absorption in the NIR II spectral region.…”

Biomimetic strategies to produce catalytically reactive CuS nanodisks

“…While great advances in synthesizing CuS structures have been achieved to control the plasmon, [12][13][14] band gap, 10,15 and morphology of these materials, 16 these methods generally require unsustainable conditions. [17][18][19][20] In this regard, CuS production typically requires harsh conditions, toxic organic solvents, 21 and/or complex instrumentation that can limit their long-term production.…”