Growth of BiSBr Microsheet Arrays for Enhanced Photovoltaics Performance.

Area of Science:

• Materials Science
• Solid-State Physics
• Photovoltaics

Background:

• Bismuth oxybromide (BiSBr) is explored for its photoelectric properties.
• Understanding its semiconductor characteristics is crucial for optoelectronic applications.

Purpose of the Study:

• To synthesize and characterize single-crystalline BiSBr.
• To evaluate its photovoltaic performance in solar cell devices.
• To investigate the impact of film morphology on device efficiency.

Main Methods:

• Solution-based synthesis of single-crystalline BiSBr.
• UV photoelectron spectroscopy and density functional theory (DFT) calculations.
• Fabrication of BiSBr films using physical vapor deposition (PVD), solvothermal, and thermal treatments.
• Fabrication and testing of solar cells with FTO/TiO2/BiSBr/(I3-/I-)/Pt architecture.

Main Results:

• BiSBr identified as an indirect p-type semiconductor with specific band edge positions.
• High electrical conductivity (14,800 S m⁻¹) along the c-axis of BiSBr single crystal microrods.
• BiSBr microsheet array solar cells achieved 1.40% power conversion efficiency, ~11 times higher than BiSBr microsheet films.
• Effective light scattering and efficient electron-hole separation/transport observed in microsheet array films.

Conclusions:

• BiSBr microsheet arrays, synthesized via low-cost solution processes, show significant potential as light absorbers.
• Optimized morphology enhances photovoltaic performance through improved light management and charge transport.
• BiSBr is a promising material for next-generation photovoltaic devices.