Honeycomb RhI₃ Flakes with High Environmental Stability for Optoelectronics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) layered transition metal trihalides (MX3) are of significant interest due to their unique properties.
• Expanding the library of 2D MX3 materials is crucial for discovering new physical phenomena and functionalities.

Purpose of the Study:

• To investigate the optical, electrical, and photodetection properties of atomically thin Rhodium Triiodide (RhI3) flakes.
• To assess the potential of RhI3 as a material for 2D electronic and optoelectronic devices.

Main Methods:

• Exfoliation of atomically thin RhI3 flakes from bulk crystals.
• Characterization of material properties using techniques such as field-effect transistor measurements and photodetector fabrication.
• Analysis of thickness-dependent bandgap, semiconducting behavior, and photodetection performance.

Main Results:

• RhI3 flakes demonstrate superior air and thermal stability.
• A thickness-dependent bandgap was observed, ranging from 1.1 eV (18 layers) to 1.4 eV (2 layers).
• Field-effect transistors exhibited n-type semiconducting behavior with a mobility of 2.5 cm2 V-1 s-1 and an ON/OFF ratio of 4 × 10^4.
• RhI3 photodetectors showed high responsivity (11.5 A W-1) and specific detectivity (2 × 10^10 Jones) at room temperature under 980 nm illumination.

Conclusions:

• Atomically thin RhI3 is a stable 2D material with promising electronic and optoelectronic characteristics.
• The observed properties suggest significant potential for RhI3 in the development of next-generation 2D electronic and optoelectronic devices.
• Further research into RhI3 could unlock novel applications in various fields.