Subsuming the Metal Seed to Transform Binary Metal Chalcogenide Nanocrystals into Multinary Compositions

Abstract

Direct colloidal synthesis of multinary metal chalcogenide nanocrystals typically develops dynamically from the binary metal chalcogenide nanocrystals with the subsequent incorporation of additional metal cations from solution during the growth process. Metal seeding of binary and multinary chalcogenides is also established, although the seed is solely a catalyst for nanocrystal nucleation and the metal from the seed has never been exploited as active alloying nuclei. Here we form colloidal Cu–Bi–Zn–S nanorods (NRs) from Bi-seeded Cu 2– x S heterostructures. The evolution of these homogeneously alloyed NRs is driven by the dissolution of the Bi-rich seed and recrystallization of the Cu-rich stem into a transitional segment, followed by the incorporation of Zn 2+ to form the quaternary Cu–Bi–Zn–S composition. The present study also reveals that the variation of Zn concentration in the NRs modulates the aspect ratio and affects the nature of the majority charge carriers. The NRs exhibit promising thermoelectric properties with very low thermal conductivity values of 0.45 and 0.65 W/mK at 775 and 605 K, respectively, for Zn-poor and Zn-rich NRs. This study highlights the potential of metal seed alloying as a direct growth route to achieving homogeneously alloyed NRs compositions that are not possible by conventional direct methods or by postsynthetic transformations.

Engineering polymorphs in colloidal metal dichalcogenides: precursor-mediated phase control, molecular insights into crystallisation kinetics and promising electrochemical activity

“…16 Contrary to this, solution-phase colloidal synthesis approaches allow more kinetic control by attaining an optimum monomer supply rate. 5,[17][18][19] In recent years, colloidal chemistry provided a viable way to obtain metastable phases and thermodynamically stable phases of various metal chalcogenides. The variable phases can be obtained by strategically manipulating the precursor and ligand chemistry to access kinetic growth domains.…”

Maneuvering Tellurium Chemistry to Design Metal–Telluride Heterostructures for Diverse Applications

“…These materials can couple and regulate the spectral absorption range as well as promote charge transfer and are extensively studied in thermoelectric, photovoltaics, catalysis, and several leading energy applications. − ,− The chemical synthesis and structural modulation of these heterostructures have witnessed newer heights with every passing year. Among the chalcogenide heterostructures, sulfides and selenides have been systematically investigated. ,,,− But, due to their lower abundance, metal–telluride heterostructures have received scant attention and put forward a lot of room to foster future research.…”

Sulfur-source-dependent phase-selective preparation of Cu3NiInSnS6nanocrystals and their optical and magnetic properties

“…Multinary metal chalcogenide compounds have received considerable attention owing to their easily tunable structure, composition and morphology, as well as the resulting unique physical and chemical properties, [1][2][3][4][5][6] enabling extensive applications in many fields, such as photovoltaics, [7][8][9] illumination, 10 photocatalysis, [11][12][13] electrocatalysis, [14][15][16] sodium-ion batteries, 17,18 sensors, 3 biology, 19 medical 20 and so on. With the transition from the simplest binary elemental compositions to more complex multiple compositions through doping or alloying, the properties and applications of materials have undergone an interesting evolution, [21][22][23][24] such as ternary I-III-VI 2 group CuInS 2 (CIS) semiconductors, 25 I-III-VI 2 group alloyed Cu(In,Ga)(Se,S) 2 (CIGS) semiconductors, 26,27 and quaternary I 2 -II-IV-VI 4 group Cu 2 ZnSnS 4 (CZTS) semiconductors 28 etc., due to their ability to allow wide band gap modulation, high absorption coefficients, and lower toxicity compared with Cd/Pb compounds. They have driven tremendous efforts to develop low-cost photovoltaic devices based on multinary chalcogenides.…”