Lead-Free Perovskite Cs₂AgNa_1-BiIn_1-Cl₆ Microcrystals for Scattering-Fluorescent Luminescent Solar Concentrators

Area of Science:

• Materials Science
• Photovoltaics
• Nanotechnology

Background:

• Luminescent solar concentrators (LSCs) are crucial for transparent building-integrated photovoltaics (BIPVs).
• Existing LSCs often focus on limited spectral ranges, hindering full solar spectrum utilization.
• There is a need for efficient, stable, and spectrally broad LSC materials.

Purpose of the Study:

• To develop a lead-free perovskite phosphor for bifunctional luminescent down-shifting (LDS) and light scattering in LSCs.
• To enhance the light response of LSCs across the ultraviolet (UV) to near-infrared (NIR) regions.
• To improve the power conversion efficiency (PCE) and stability of LSC-based photovoltaic systems.

Main Methods:

• Fabrication of LSCs using a novel lead-free microcrystal Cs2AgNa1-xBiIn1-xCl6 (CANBIC) perovskite phosphor.
• Characterization of optical efficiency (ηopt) and average visible transmission (AVT).
• Integration with silicon (Si) solar cells (single-edge and four-edge mounted) and use of Al foil as a reflection background.

Main Results:

• Optimized CANBIC content (30 mg) achieved an optical efficiency (ηopt) of 5.40% and AVT >50%.
• LSC-PV systems demonstrated improved short-circuit current density (JSC) up to 1.232 mA/cm².
• The LSC-4PV system with Al foil achieved a champion PCE of 3.14% and JSC of 7.94 mA/cm².
• The LSC exhibited superior stability under UV illumination and ambient air exposure.

Conclusions:

• The CANBIC perovskite phosphor shows bifunctional LDS and light scattering capabilities for broad spectral response LSCs.
• The developed LSCs significantly enhance PCEs for edge-mounted Si solar cells, promising for BIPVs.
• The material demonstrates excellent stability, making it suitable for practical applications.