Performance enhancement in CZTSSe solar cells via BaSi₂ back surface field integration

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Kesterite-based CZTSSe solar cells face efficiency limitations due to low open-circuit voltage (V_OC).
• Optimizing absorber and interface properties is crucial for enhancing solar cell performance and stability.
• Thermal stability and operating temperature effects on photovoltaic parameters require careful evaluation.

Purpose of the Study:

• To enhance the simulated performance of CZTSSe solar cells by optimizing absorber and interface properties.
• To investigate the impact of a BaSi₂-based back surface field (BSF) layer on device efficiency and V_OC losses.
• To evaluate the thermal stability of the proposed solar cell structure under varying operating temperatures.

Main Methods:

• Numerical simulations were performed using SCAPS-1D software to model CZTSSe solar cells.
• A BaSi₂-based BSF layer was incorporated to mitigate V_OC-related losses.
• Systematic studies on CZTSSe absorber layer thickness (0.5–3 μm) and doping concentration (10¹²–10¹⁸ cm^-3) were conducted.

Main Results:

• Incorporating the BaSi₂ BSF layer increased simulated efficiency from 12.54% to 16.37%.
• The BaSi₂ BSF layer effectively reduced V_OC-related losses, improving overall device performance.
• Optimal CZTSSe absorber thickness and doping concentration were determined, leading to a simulated efficiency of 19.61% under idealized conditions.

Conclusions:

• The BaSi₂-based BSF layer is a promising strategy for enhancing CZTSSe solar cell efficiency.
• Optimizing absorber layer thickness and doping concentration further improves device performance.
• While reduced thickness can enhance minority carrier lifetime, it presents challenges for experimental realization.