Strong optical absorption in cubic RaMS₃ chalcogenide perovskites for optoelectronic applications: a first-principles...

Area of Science:

• Materials Science
• Solid State Physics
• Inorganic Chemistry

Background:

• Chalcogenide perovskites offer tunable optoelectronic properties.
• Cubic phases, especially with transition metals and large cations, are underexplored.
• RaMS3 (M = Ti, Zr, Hf) represents a new family of cubic chalcogenide perovskites.

Purpose of the Study:

• To theoretically investigate the structural, electronic, optical, and mechanical properties of RaMS3 perovskites.
• To explore the potential of these materials for optoelectronic applications.
• To understand the stability of the cubic phase in these novel compounds.

Main Methods:

• First-principles calculations using hybrid functionals.
• Density-of-states (DOS) analysis.
• Phonon calculations (harmonic and anharmonic self-consistent phonon methods).

Main Results:

• All three RaMS3 compounds are indirect-band-gap semiconductors (0.47–1.54 eV).
• Valence bands are S-p states; conduction bands are transition-metal d states.
• RaZrS3 and RaHfS3 show strong visible-light absorption and high predicted efficiencies (22-30%).
• Cubic RaZrS3 and RaHfS3 are dynamically stable; RaTiS3 becomes stable at 300 K due to anharmonic effects.

Conclusions:

• Cubic RaMS3 perovskites present tunable electronic and optical properties.
• These materials are promising for optoelectronic applications, particularly solar cells.
• Understanding their stability, especially at finite temperatures, is crucial for material design.