Ribbons of Light: Emerging (Sb,Bi)(S,Se)(Br,I) Van der Waals Chalcohalides for Next-Generation Energy Applications

Area of Science:

• Materials Science
• Solid State Chemistry
• Energy Science

Background:

• Van der Waals (VdW) semiconductors are crucial for next-generation energy devices.
• Pnictogen chalcohalides, with their unique electronic and structural properties, are emerging as promising candidates.
• Existing synthesis methods may limit the exploration and application of these materials.

Purpose of the Study:

• To develop a versatile synthesis methodology for a range of (Sb,Bi)(S,Se)(Br,I) pnictogen chalcohalides.
• To comprehensively characterize their structural, compositional, and optoelectronic properties.
• To demonstrate their potential for practical energy applications.

Main Methods:

• Co-evaporation of binary chalcogenides.
• Reactive annealing under high-pressure halide atmospheres.
• Structural, compositional, and optoelectronic analyses (e.g., X-ray diffraction, UV-Vis spectroscopy, microscopy).

Main Results:

• Successful fabrication of eight (Sb,Bi)(S,Se)(Br,I) chalcohalides with quasi-1D orthorhombic structure.
• Demonstrated wide bandgap tunability (1.2-2.2 eV) and high absorption coefficients.
• Observed anisotropic properties, high stability, chemical adaptability, and defect tolerance.

Conclusions:

• The developed synthesis method is versatile and adaptable for creating diverse pnictogen chalcohalides.
• These materials exhibit promising optoelectronic properties and stability for energy applications.
• This work lays the foundation for scalable and eco-friendly pnictogen chalcohalide-based energy devices.