Multiscale quantum-to-device simulation framework for Ca₃AsBr₃ perovskite solar cells: engineering efficient electron...

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Perovskite solar cells (PSCs) are promising for renewable energy but often rely on toxic or unstable materials.
• There is a growing need for environmentally benign, stable, and high-performance absorber materials in PSC development.

Purpose of the Study:

• To evaluate the optoelectronic and mechanical properties of Ca3AsBr3, a non-toxic halide perovskite, for photovoltaic applications.
• To investigate the performance of PSC devices using Ca3AsBr3 as an absorber with various electron transport layers (ETLs).
• To identify optimal device parameters for maximizing power conversion efficiency (PCE).

Main Methods:

• Density Functional Theory (DFT) calculations were used to assess material properties.
• SCAPS-1D simulations were employed to model device performance with different ETLs (WS2, SnS2, CdS, TiO2).
• Analysis included energy band alignment, defect tolerance, and device efficiency metrics.

Main Results:

• Ca3AsBr3 exhibits a direct bandgap of 1.66 eV, good mechanical stability, and strong optical absorption.
• A PSC device with WS2 as the ETL achieved a high PCE of 20.50%, with Voc = 1.165 V, Jsc = 20.55 mA/cm², and FF = 85.64%.
• Optimal absorber thickness (1200 nm) and reduced defect densities (≤10^15 cm⁻³ bulk, ≤10^13 cm⁻² interface) are crucial for minimizing losses.

Conclusions:

• Ca3AsBr3 is identified as a viable, eco-friendly absorber material for high-performance PSCs.
• Optimization of ETLs and absorber properties is critical for efficient and stable PSC devices.
• This research contributes to the development of scalable and environmentally conscious solar energy technologies.