The Presence of Charge Transfer Defect Complexes in Intermediate Band CuAl1−pFepS2

Dickens, Christopher, Kinsella, Adam O. J., Watkins, Matt and Booth, Matthew (2022) The Presence of Charge Transfer Defect Complexes in Intermediate Band CuAl1−pFepS2. Crystals, 12 (12). p. 1823. ISSN 2073-4352

Full content URL: https://doi.org/10.3390/cryst12121823

Documents
The Presence of Charge Transfer Defect Complexes in Intermediate Band CuAl1−pFepS2
Published manuscript
[img]
[Download]
[img]
Preview
PDF
crystals-12-01823-v2.pdf - Whole Document
Available under License Creative Commons Attribution 4.0 International.

11MB
Item Type:Article
Item Status:Live Archive

Abstract

Despite chalcopyrite (CuFeS2) being one of the oldest known copper ores, it exhibits various properties that are still the subject of debate. For example, the relative concentrations of the ionic states of Fe and Cu in CuFeS2 can vary significantly between different studies. The presence of a plasmon-like resonance in the visible absorption spectrum of CuFeS2 nanocrystals has driven a renewed interest in this material over recent years. The successful synthesis of CuAl1−pFepS2 nanocrystals that exhibit a similar optical resonance has recently been demonstrated in the literature. In this study, we use density functional theory to investigate Fe substitution in CuAlS2 and find that the formation energy of neutral [FeCu]2++[CuAl]2− defect complexes is comparable to [FeAl]0 antisites when p≥0.5. Analysis of electron density and density of states reveals that charge transfer within these defect complexes leads to the formation of local Cu2+/Fe2+ ionic states that have previously been associated with the optical resonance in the visible absorption of CuFeS2. Finally, we comment on the nature of the optical resonance in CuAl1−pFepS2 in light of our results and discuss the potential for tuning the optical properties of similar systems.

Keywords:crystal, semiconductor, defects, charge transfer
Subjects:F Physical Sciences > F200 Materials Science
F Physical Sciences > F120 Inorganic Chemistry
F Physical Sciences > F343 Computational Physics
F Physical Sciences > F310 Applied Physics
F Physical Sciences > F321 Solid state Physics
Divisions:College of Science > School of Mathematics and Physics
ID Code:54149
Deposited On:04 Apr 2023 15:57

Repository Staff Only: item control page