Systematic Bandgap Engineering of a 2D Organic-Inorganic Chalcogenide Semiconductor via Ligand Modification

Area of Science:

• Materials Science
• Solid-State Physics
• Organic Chemistry

Background:

• Hybrid organic-inorganic semiconductors offer unique optoelectronic properties.
• Silver phenylselenide (AgSePh), or mithrene, is a 2D semiconductor with anisotropic characteristics.
• Existing materials lack the tunable properties desired for advanced applications.

Purpose of the Study:

• To investigate the bandgap tunability of mithrene derivatives.
• To explore the impact of chemical modifications on semiconductor properties.
• To establish predictive correlations for bandgap engineering.

Main Methods:

• Synthesis of nine mithrene variants with varied phenyl ligands.
• Characterization of 2D van der Waals crystal formation.
• Density functional theory (DFT) calculations for electronic structure analysis.
• Correlation analysis between optical gap and experimental observables (Hammett constant, 77Se chemical shift, selenium partial charge).

Main Results:

• Eight new 2D van der Waals crystalline mithrene variants were synthesized.
• DFT calculations confirmed direct or near-direct bandgaps for these variants.
• Established quantitative correlations between the optical gap and chemical descriptors.
• Demonstrated predictive power for bandgap tuning through chemical synthesis.

Conclusions:

• Chemical synthesis offers a powerful route for designing tunable hybrid semiconductor materials.
• Mithrene derivatives provide a versatile platform for optoelectronic applications.
• The identified correlations enable rational design of semiconductors with desired bandgaps.