ART-PV India develops tandem solar cell with 29.8% efficiency

How the tandem cell works

ART-PV’s tandem solar cell stacks two layers to capture a broader spectrum of sunlight. The bottom layer uses silicon or cadmium telluride (CdTe), while the top layer is made of perovskite, a material whose absorption properties can be chemically tuned. This design addresses the inefficiencies of single-junction silicon cells, which waste certain wavelengths of light.

The cell is monolithic, meaning the layers are grown as a single device, and two-terminal, allowing it to connect electrically like a conventional solar panel. This compatibility could simplify integration into existing solar farms or rooftop installations.

Performance and industry backing

The company has achieved a 29.8% conversion efficiency in laboratory tests, surpassing the theoretical limit of single-junction silicon cells, which max out at around 29%. This figure, however, reflects a small-scale cell measurement, and full-sized modules typically perform lower.

First Solar, a major thin-film solar manufacturer with a plant near Chennai, and Waaree, India’s largest crystalline silicon panel maker, are industry partners. Both hold preferential licensing rights for ART-PV’s technology, positioning them to commercialise it at scale.

Government funding and facility

The Ministry of New and Renewable Energy has allocated approximately $10 million to build a pilot manufacturing facility for ART-PV on the IIT Bombay campus. The facility aims to produce commercial-grade tandem cells rather than laboratory samples.

ART-PV operates from a 5,000 sq ft ISO 7 cleanroom at IIT Bombay’s research park, equipped with fabrication, characterisation, and simulation tools. The startup benefits from the National Centre for Photovoltaic Research and Education, which has received over Rs 200 crore in funding since 2010.

Union Minister Pralhad Joshi reportedly described the technology as a national milestone during a visit, emphasising the government’s intent to retain intellectual property within India.

Challenges ahead

While the efficiency milestone is significant, perovskite-based cells face durability issues. The material degrades under heat, moisture, and ultraviolet light, a problem that extends to tandem cells using perovskite as the top layer.

ART-PV has not yet published module-level efficiency data, durability test results, or a commercial production timeline. These factors will determine the technology’s viability for large-scale deployment.

What this means

Lazyfounder analysis — our interpretation, not reported fact.

ART-PV’s breakthrough highlights the potential for tandem solar cells to push beyond the limits of silicon, a development that could redefine the solar industry’s efficiency benchmarks. For founders and operators, this signals a shift toward materials and architectures that were once considered experimental but are now gaining commercial traction. The involvement of established players like First Solar and Waaree suggests that tandem cells could move from labs to production lines faster than expected, especially with government backing.

However, the durability challenges of perovskite remain a critical hurdle. Founders eyeing this space will need to weigh the efficiency gains against the engineering and cost barriers of making the technology reliable for long-term use. The domestic focus on intellectual property and manufacturing could also create opportunities for local startups to collaborate with research institutions or explore adjacent innovations in solar materials.

Key takeaways

• Founders in the solar sector can view tandem cell technology as a potential disruptor, offering efficiency gains beyond traditional silicon limits.
• The involvement of major industry players like First Solar and Waaree signals commercial validation for ART-PV’s approach, which could accelerate adoption.
• The government funding and domestic IP focus may encourage local manufacturers to explore partnerships or similar R&D investments.
• Durability remains an unresolved challenge for perovskite-based cells, which could impact timelines for commercial viability.