Ternary Antimony Selenide Semiconductors: Synthesis, Crystal Structure, Electronic Structure, and Optical Properties

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Antimony chalcogenides are emerging as promising semiconductor materials for optoelectronic applications.
• Previous research has focused on binary antimony selenides, necessitating exploration of ternary compounds.

Purpose of the Study:

• To synthesize and characterize novel ternary antimony chalcogenides, specifically SrSbSe3 and Sr3Sb4Se9.
• To investigate the crystal structures and optoelectronic properties of these new compounds.
• To evaluate their potential for optoelectronic applications.

Main Methods:

• Single-crystal X-ray diffraction (XRD) for structural determination.
• Second-harmonic generation (SHG) measurements to confirm noncentrosymmetric structure.
• Optical absorption and effective mass calculations to assess optoelectronic properties.

Main Results:

• SrSbSe3 crystallizes in a noncentrosymmetric space group (P212121) with a notable SHG response.
• Sr3Sb4Se9 crystallizes in a centrosymmetric space group (Pnma).
• Both compounds exhibit quasi-direct bandgaps (~0.96-0.98 eV), high optical absorptions (>10^5 cm^-1) above 1.3 eV, and small effective masses, comparable to Sb2Se3.
• Key optoelectronic transitions are aligned with [Sb4Se9]6- double-ribbon chains.

Conclusions:

• SrSbSe3 and Sr3Sb4Se9 are promising ternary antimony chalcogenides with significant optoelectronic potential.
• Their unique crystal structures and favorable electronic band structures make them suitable for optoelectronic devices.
• Further research into these materials could lead to advancements in semiconductor technology.