Issue 37, 2022

Vacancy assisted growth of copper tantalum sulfide nanocrystals

Abstract

Cu-based ternary chalcogenides have received significant interest as an alternative to conventional photovoltaic materials. CuInS2 and CuInSe2 are the most studied copper-based ternary chalcogenides for photovoltaics. Recently, copper tantalum sulfide (CuTaS3) has been proposed as a potential light absorber for photovoltaics. The synthesis conditions and growth mechanism of ternary systems control the final composition and crystal structure. However, such studies have not been explored for copper tantalum sulfides. Here, we studied the formation and growth mechanism of Cu3TaS4 nanocrystals (NCs) primarily using X-ray diffraction, transmission electron microscopy, and density functional theory (DFT) calculations. The reactions proceed via the formation of cubic Cu2−xS NCs due to soft Lewis acid – soft Lewis base interaction. The Cu2−xS have Cu vacancies, which can be controlled by the relative concentration of the Cu precursor. Ta incorporation occurs in the Cu2−xS NCs at Cu vacancy sites, followed by the diffusion of Ta by replacing Cu into the lattice. Low packing of atoms in Cu3TaS4 provides suitable diffusion channels for Ta and Cu atoms. The diffusion barriers of Ta atoms outweigh that of Cu atoms, implying a reaction rate controlled by Ta diffusion. Thus by varying the relative Cu precursor concentration, the concentration of Cu-vacancies in Cu2−xS can be tuned, which controls the growth rate of Cu3TaS4. Understanding of the growth mechanism obtained in this paper will significantly contribute to the rational synthesis of various Cu-based ternary chalcogenides that is not possible by direct synthesis and hence will have an impact on potential applications in photovoltaics and photocatalysis.

Graphical abstract: Vacancy assisted growth of copper tantalum sulfide nanocrystals

Supplementary files

Article information

Article type
Paper
Submitted
04 apr 2022
Accepted
01 jun 2022
First published
06 jun 2022

J. Mater. Chem. A, 2022,10, 19925-19934

Vacancy assisted growth of copper tantalum sulfide nanocrystals

A. Haque, S. Ershadrad, T. D. Chonamada, D. Saha, B. Sanyal and P. K. Santra, J. Mater. Chem. A, 2022, 10, 19925 DOI: 10.1039/D2TA02714C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements