Electron extraction layer-driven performance enhancement in CaHfSe₃ photovoltaics

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Traditional solar cells face challenges like instability, cost, and toxicity (e.g., silicon, lead-halide perovskites).
• There's a need for novel, stable, and environmentally benign absorber materials for next-generation photovoltaics.

Purpose of the Study:

• To evaluate Calcium Hafnium Selenide (CaHfSe3) as a lead-free, thermally stable absorber for solar cells.
• To optimize device performance through comprehensive numerical simulations and experimental validation.

Main Methods:

• Utilized SCAPS-1D for numerical simulations of various device topologies.
• Conducted parametric studies on absorber thickness, defect density, doping, and carrier concentrations.
• Performed experimental analysis of operational characteristics, including I-V curves and quantum efficiency.

Main Results:

• Identified an optimized structure: FTO/TiO2/CaHfSe3/MoO3/Au.
• Achieved a record power conversion efficiency (PCE) of 32.39% with V_OC = 1.52 V, J_SC = 23.17 mA cm⁻², and FF = 91.41%.
• Demonstrated the material's stability and potential for high performance.

Conclusions:

• CaHfSe3 is a highly promising material for developing efficient, stable, and eco-friendly solar cells.
• The findings provide fundamental insights and practical guidance for CaHfSe3-based photovoltaic development.
• This research supports the future experimental realization and commercialization of advanced solar technologies.