[Paper Review] First-principles discovery of stable, anisotropic, semiconducting Sb2X2O (X = S, Se) and Janus Sb2SSeO nanosheets for optoelectronics and photocatalysis

Masoud Shahrokhi, Bohayra Mortazavi|arXiv (Cornell University)|Feb 9, 2026

2D Materials and Applications0 citations

TL;DR

Using first-principles calculations, the authors predict stable, anisotropic Sb2X2O (X = S, Se) and Janus Sb2SSeO monolayers with tunable optoelectronic properties and potential for water-splitting photocatalysis and directional device applications.

ABSTRACT

In this work, we conduct a comprehensive first-principles investigation into the design and discovery of novel antimony oxychalcogenide monolayers Sb2X2O (X = S, Se) and Janus Sb2SSeO, examining their structural stability, elastic, electronic, optoelectronic, and photocatalytic properties. Our analysis confirms their thermodynamic and dynamical stability and reveals low cleavage energies, indicating strong feasibility for mechanical exfoliation. The excellent agreement between our HSE06-predicted bandgap of bulk Sb2S2O and experimental measurements further validates the employed computational framework. EWe also find that their optoelectronic responses can be efficiently tuned via biaxial strain, providing a viable route for device-specific property engineering. Favorable band alignments, strong optical absorption, efficient carrier transport, and relatively high dielectric constants collectively support their candidacy for overall water splitting under neutral conditions.These results establish a solid theoretical foundation for the rational design of Sb-based 2D nanostructures and highlight their potential in next-generation direction-dependent optoelectronic and sustainable energy-conversion applications.

Motivation & Objective

• Design and assess Sb-based oxychalcogenide monolayers Sb2X2O (X = S, Se) and Janus Sb2SSeO for stability, structure, and properties.
• Evaluate elastic, electronic, optoelectronic, and photocatalytic potential of these 2D materials.
• Identify feasible synthesis routes via low cleavage energies and exfoliation feasibility.
• Explore strain engineering as a route to tailor device-relevant properties.

Proposed method

• First-principles calculations (density functional theory) to assess structural stability and dynamics.
• Phonon analysis to establish dynamical stability.
• Calculation of cleavage energies to gauge mechanical exfoliation feasibility.
• Electronic structure calculations including HSE06 for accurate bandgaps.
• Assessment of optoelectronic response and dielectric properties.
• Simulation of biaxial strain effects on electronic and optical properties.

Experimental results

Research questions

• RQ1 Are Sb2X2O (X = S, Se) and Janus Sb2SSeO thermodynamically and dynamically stable as 2D monolayers?
• RQ2 Can these materials be efficiently exfoliated from bulk based on cleavage energies?
• RQ3 How do biaxial strains influence bandgaps, band alignments, and optical responses?
• RQ4 Do the materials exhibit properties favorable for water-splitting and optoelectronic applications?

Key findings

• Sb2X2O (X = S, Se) and Janus Sb2SSeO are thermodynamically and dynamically stable as 2D monolayers.
• Low cleavage energies indicate strong feasibility for mechanical exfoliation.
• HSE06-predicted bulk Sb2S2O bandgap shows excellent agreement with experiment.
• Biaxial strain can efficiently tune optoelectronic responses and device-relevant properties.
• Band alignments, strong optical absorption, good carrier transport, and high dielectric constants support photocatalytic water splitting under neutral conditions.
• The results establish a solid theoretical framework for designing Sb-based 2D nanostructures for direction-dependent optoelectronics and energy conversion.