Tl2S

thallium(I) sulfide · thallous sulfide

Thallium(I) sulfide is a stable semiconducting compound frequently investigated for its utility in infrared sensing and optical applications.

STl
Crystal structure of Tl2S (trigonal, R3 (No. 146))
Ground-state structure · Materials Project
Overview

About thallium(I) sulfide

Thallium(I) sulfide is a distinct binary chalcogenide that exists as a thermodynamically stable phase on the convex hull. Its electronic character as a semiconductor makes it a subject of interest for specialized optoelectronic research and material characterization studies.

With a significant number of reported structures across various databases, this compound demonstrates a complex structural landscape. It is primarily utilized in the development of sensitive infrared detection equipment and specialized optical components where its unique electronic properties can be leveraged.

At a glance

Key Properties

Cross-validated computational properties for thallium(I) sulfide, aggregated across 4 databases.

Band Gap

0.77–1.13 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

21
4 databases, 5 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for Tl2S, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
R3 (No. 146)trigonal0.770.0000-3.4657.50
P31m (No. 157)trigonal1.130.0002-38.5557.94
R3 (No. 146)trigonal0.890.0011-3.4647.99
P3 (No. 143)trigonal0.960.0015-3.4647.96
P3 (No. 143)Trigonal7.90
No. 0unknown1.78
Cmmm (No. 65)Orthorhombic6.56
P3 (No. 143)Trigonal7.96
P3 (No. 143)Trigonal7.96
P3 (No. 143)
R3 (No. 146)Trigonal7.70
P3 (No. 143)Trigonal7.61
Uses

Applications

Where thallium(I) sulfide is used.

Infrared detectorsPhotoconductive cellsOptical coatings
Reference

Frequently Asked Questions

Common questions about thallium(I) sulfide, answered from cross-validated data.

What is Tl2S?

Thallium(I) sulfide is a stable semiconducting compound frequently investigated for its utility in infrared sensing and optical applications.

More questions
What is Tl2S used for?
thallium(I) sulfide (Tl2S) is used in infrared detectors, photoconductive cells, and optical coatings.
What is the band gap of Tl2S?
thallium(I) sulfide (Tl2S) has a DFT-computed band gap of 0.77–1.13 eV across 21 reported structures.
Is Tl2S a metal, semiconductor, or insulator?
With a band gap up to 1.13 eV it is a semiconductor.
Is Tl2S thermodynamically stable?
Yes — thallium(I) sulfide (Tl2S) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of Tl2S?
The lowest-energy reported polymorph of thallium(I) sulfide (Tl2S) is trigonal symmetry, space group R3 (No. 146).
What is the density of Tl2S?
The computed density of the ground-state structure of thallium(I) sulfide (Tl2S) is 7.50 g/cm³.
How many polymorphs of Tl2S are known?
21 structures of Tl2S are reported across 4 databases, spanning 5 distinct space groups.
What elements does Tl2S contain?
thallium(I) sulfide (Tl2S) contains S and Tl (2 elements).
Where does the data for Tl2S come from?
Tl2S data is cross-referenced from materials_project, mpaloe, cod, jarvis.
Comparison

How It Compares

As a standalone binary chalcogenide, thallium(I) sulfide serves as a fundamental reference point for understanding the behavior of heavy-metal sulfides. It occupies a unique position in materials science due to its stability and semiconducting nature, which distinguish it from more common, less stable thallium-based compounds.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • mpaloe — Data from mpaloe.
  • cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).

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