Issue 21, 2025

Unveiling the unique site preference of Ga in the defect wurtzite type In2Se3–Ga2Se3 system: an experimental and computational study

Abstract

The pseudo-binary phases in the In2Se3–Ga2Se3 system have drawn attention due to their interesting structural features and exciting non-linear optical (NLO) properties. Although the phases have been known since 1977, detailed structural characterization has not been carried out in previous studies. In this research program, the pseudo-binary In2−xGaxSe3 (x = 0.6–1.4) (hexagonal, P65/P61) has been prepared using high-temperature synthesis and characterized using X-ray diffraction techniques and DFT calculations. For x ≤ 1, the structure is similar to the parent γ-In2Se3 and adopts the layered defect wurtzite type (γ1), where gallium preferentially substitutes the tetrahedrally coordinated indium site without affecting the indium in the trigonal bipyramidal (TBP) environment. At x = 1, the ordered γ1-GaInSe3 is formed. In the compositional range 1.2 < x ≤ 1.4, an ideal defect wurtzite structure (γ2) is observed, where both cationic sites are tetrahedrally coordinated by selenium. Ga occupies one of the two tetrahedrally coordinated cationic sites in this region, while the other site is statistically occupied by Ga and In. Interestingly, at x = 1.2, the structure is heavily disordered and can be interpreted as an incoherent intergrowth of γ1- and γ2-phases. A detailed theoretical calculation is performed on various compounds in the III2–VI3 family (e.g., α-Al2S3, α-Ga2S3, γ-In2Se3, and InGaSe3) to reveal the preference of Ga for tetrahedral co-ordination in the pseudo-binary In2−xGaxSe3.

Graphical abstract: Unveiling the unique site preference of Ga in the defect wurtzite type In2Se3–Ga2Se3 system: an experimental and computational study

Supplementary files

Article information

Article type
Paper
Submitted
29 Jan 2025
Accepted
11 Apr 2025
First published
18 Apr 2025

Dalton Trans., 2025,54, 8673-8682

Unveiling the unique site preference of Ga in the defect wurtzite type In2Se3–Ga2Se3 system: an experimental and computational study

S. S. Sethi, A. Lakshan, A. Roy, S. Das, K. Das and P. P. Jana, Dalton Trans., 2025, 54, 8673 DOI: 10.1039/D5DT00231A

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