Charge Transfer Modulation in Vanadium-Doped WS₂ /Bi₂ O₂ Se Heterostructures

Area of Science:

• Materials Science
• Condensed Matter Physics
• Renewable Energy

Background:

• Two-dimensional (2D) type-II heterostructures are revolutionizing photovoltaics by capturing a broader solar spectrum.
• Tungsten disulfide (WS₂) and bismuth oxychalcogenide (Bi₂O₂Se) are promising materials for high-performance photovoltaic devices.

Purpose of the Study:

• To investigate the potential of vanadium (V)-doped WS₂ (V-WS₂) combined with Bi₂O₂Se for advanced photovoltaic applications.
• To explore the impact of V-doping on charge transfer dynamics in WS₂/Bi₂O₂Se heterostructures.

Main Methods:

• Fabrication and characterization of WS₂/Bi₂O₂Se and V-WS₂/Bi₂O₂Se heterostructures.
• Photoluminescence (PL) spectroscopy to assess charge transfer efficiency.
• Raman spectroscopy and Kelvin probe force microscopy (KPFM) for structural and electronic analysis.

Main Results:

• Significant quenching of PL by 40% (WS₂/Bi₂O₂Se), 95% (0.4 at.% V-WS₂/Bi₂O₂Se), and 97% (2 at.% V-WS₂/Bi₂O₂Se) indicates enhanced charge transfer with V-doping.
• Exciton binding energies were reduced from ≈130 meV (WS₂/Bi₂O₂Se) to ≈80 meV (2 at.% V-WS₂/Bi₂O₂Se), surpassing monolayer WS₂.
• V-doping effectively tunes charge transfer in WS₂/Bi₂O₂Se heterostructures.

Conclusions:

• Vanadium-doped WS₂/Bi₂O₂Se heterostructures demonstrate superior charge transfer capabilities compared to pristine WS₂/Bi₂O₂Se.
• This V-doped TMDC/Bi₂O₂Se system offers a novel light-harvesting strategy for next-generation photovoltaic devices.
• The tunable electronic properties of V-doped WS₂ present a promising avenue for advancing solar energy conversion technologies.