Single junction CsPbBr₃ solar cell coupled with electrolyzer for solar water splitting

Area of Science:

• Renewable Energy
• Materials Science
• Photochemistry

Background:

• Artificial photosynthesis offers a sustainable solution for energy and environmental challenges.
• Current high-efficiency systems require multiple light absorbers, increasing complexity.
• Natural photosynthesis has lower efficiency compared to artificial systems.

Purpose of the Study:

• To demonstrate a single light absorber system for overall water splitting.
• To achieve efficient solar-to-hydrogen (STH) conversion using a single junction solar cell.
• To evaluate the potential of this system for future energy applications.

Main Methods:

• Utilized a photovoltaic-electrochemical (PV-EC) system.
• Employed a cesium lead bromide (CsPbBr3) solar cell with a 2.3 eV band gap.
• Integrated the solar cell with a water electrolyzer to generate hydrogen gas.

Main Results:

• Achieved a solar-to-hydrogen efficiency of 1.7% with confirmed H2 generation.
• The CsPbBr3 solar cell exhibited an open-circuit voltage exceeding 1600 mV.
• Demonstrated a potential operating point for 5.0% STH efficiency.

Conclusions:

• The single light absorber (S2) PV-EC system is a viable approach for overall water splitting.
• This technology shows prospective for significant efficiency improvements (up to 12%) and cost-effective hydrogen production ($5.5/kg).
• The study establishes a benchmark for future S2 PV-EC system development.