Alloyed CuInS₂–ZnS nanorods: synthesis, structure and optical properties

Abstract

nanocrystals are promising candidates for application in biolabeling, photocatalysis, solar energy conversion, and light emitting diodes. When charge transport is of importance, elongated nanoparticles are advantageous, because of their higher electrical conductivity compared to the quasispherical ones. However, still little is known about the growth mechanism of such nanostructures composed of quaternary materials. Here, CuInS 2-ZnS nanorods were synthesized by a heating-up method, and their Zn content was controlled by changing the composition of the reaction solution. A mixture of oleylamine and oleic acid is used as solvent. Copper, indium, and zinc acetate are the sources of the cations, while sulfur monomers stem from the thermal decomposition of tert-dodecanethiol. The growth of CuInS 2-ZnS nanorods starts with the formation of copper sulfide particles. They are gradually converted to CuInS 2-ZnS by incorporation of indium and zinc ions. Alloyed CuInS 2-ZnS nanorods are the only product, independent of the amount of zinc applied; Raman spectroscopy measurements show no separate ZnS phase. At longer reaction time, the nanorods aggregate to form dimers. The onset of the absorption and the position of the maximum of the emission as well as the fluorescence lifetime depend on the composition of the nanorods.

Comparative advantages of Zn–Cu–In–S alloy QDs in the construction of quantum dot-sensitized solar cells

“…Alloying Zn element into CIS QD is an effective method to solve this problem. [45][46][47][48] As observed in Fig. 1d, the PL efficiency of the obtained ZCIS QDs is higher than that of the core/shell structured CIS/ZnS QDs.…”

Non-stoichiometric Cu–In–S@ZnS nanoparticles produced in aqueous solutions as light harvesters for liquid-junction photoelectrochemical solar cells

“…For example, this approach was successfully employed for identication of ZnS as a secondary phase in Cu 2 ZnSnS 4 (ref. 38 and 39) and distinguishing the ZnS shell formation from Zn alloying into CIS 40 or In x S NPs. 41 The spectrum of pristine CIS NPs at l exc ¼ 488 nm is dominated by a broad complex feature at 240-400 cm À1 (Fig.…”

“…4b, curve 3) shows a distinct peak at 345 cm À1 which is a characteristic frequency of ZnS. 38,40 Importantly, observing this phonon peak enhanced at a l exc resonant with ZnS allows us to distinguish formation of the ZnS shell on the CIS NPs from Zn alloying into the CIS lattice.…”

Morphology-induced phonon spectra of CdSe/CdS nanoplatelets: core/shell vs. core–crown

“…12,[34][35][36][37][38][39] Moreover, understanding the structure of the core/shell interface for 2D II-VI NCs would facilitate modelling and application of multiple-interface NCs, including also cadmium-free heterosystems like CuInS 2 /ZnS, for instance. 40 Up to now, the phonons in ultrathin semiconductor layers were studied mainly for epitaxial superlattices (SLs) coherently grown on certain substrates. 41 Those studies were complicated by the effects of substrate induced strain and/or its relaxation via dislocations or transition to 3D island growth, as well as contribution of the Raman signal of the substrate.…”