Electronic and optical properties of disordered getchellite

The paper titled Electronic and optical properties of disordered getchellite: A photoreflectance, optical absorption, photoemission, and theoretical investigation presents the basic electronic and optical properties of a getchellite (AsSbS₃) crystal. This crystal is a disordered alloy in which As and Sb atoms are axially arranged in nodal positions (Figure 1). Moreover, AsSbS₃ is a semiconducting layered material – atoms within a given layer are covalent/ion bonded, while the van der Waals forces bond adjacent layers.

Agata Sabik — Figure 1. AsSbS3 elementary cell (left). The atoms of sulphur are marked in yellow; Diagram of the position of the valence band maximum and conduction band minimum in AsSbS3 (right).

The work presents that AsSbS₃ is a p-type semiconductor with optical properties dominated by a simple transition. The fundamental band gap of 2.31 eV at 0 K is oblique. For a single layer of the material, considered in theoretical studies, the results revealed a change in the nature of the fundamental break to a simple one.

The work Electronic and optical properties of disordered getchellite: A photoreflectance, optical absorption, photoemission, and theoretical investigation published in APL Materials (Open Access), authored by Agata Sabik, Miłosz Grodzicki, Maciej P. Polak, Sandeep Gorantli, Alicja Bachmatiuk, Robert Kudrawiec, and Wojciech M. Linhart, was done as part of the implementation of the research tasks of the OPUS NCN project titled Defect-tolerant absorbers for photovoltaic applications (project no.: 2019/35/B/ST5/02819).

Link to the paper