Indian Team Achieves 26% Efficiency with Lead-Free Perovskite-CIGS Tandem Solar Cells
India’s solar power sector continues to innovate as researchers at Visvesvaraya National Institute of Technology achieve a breakthrough. Their simulation of tandem cells combining lead-free perovskite with CIGS technology reaches 26.06% efficiency – potentially revolutionizing renewable energy adoption.
Why Tandem Solar Cells Outperform Traditional Models
Traditional single-junction panels waste significant energy through heat dissipation. The Indian team’s tandem design captures more solar spectrum by using:
- Dual absorption layers with different bandgaps
- Advanced current-matching techniques
- Optimized voltage stacking
Key Innovation: Eliminating Toxic Lead
The team replaced conventional lead-based perovskites with safer CsGeI3 compounds, pairing them with copper-indium-gallium-selenide (CIGS). This marks the first successful simulation of this eco-friendly combination in solar applications.
Breakthrough Methodology
Using SCAPS-1D simulation software, researchers developed:
- 273nm perovskite top layer (16.93% efficiency)
- 1,000nm CIGS bottom layer (16.49% efficiency)
Their novel architecture achieved 26.06% combined efficiency through precise voltage and current balancing.
Future Implications for Renewable Energy
This high-efficiency solar technology could transform energy storage economics when commercialized:
- Surpasses commercial panels’ 22-24% efficiency benchmarks
- Reduces land requirements per MW generated
- Enables easier scaling through thin-film CIGS technology
With further development, these lead-free cells could accelerate India’s transition to sustainable power while setting new global standards for photovoltaic technology.
