Rayzon and Navitas Partner Caelux to Bring 10 GW of Perovskite-Silicon Tandem Solar to India

India lines up for the tandem-solar era

Two Indian solar manufacturers — Rayzon Solar and Navitas Solar — have each signed five-year agreements with US-based perovskite specialist Caelux to manufacture perovskite-silicon tandem solar modules in India. Each deal covers 5 GW of capacity, taking the combined planned output to 10 GW, among the largest commitments yet to next-generation tandem photovoltaics in the country. The partnerships were announced in the week of 23 July 2026.

For an Indian solar industry that has spent the last three years racing to add conventional cell and module capacity, the tie-ups mark a shift in ambition: from catching up on today's silicon technology to leapfrogging toward the higher-efficiency architecture widely seen as the sector's next step.

What the companies agreed

Under the agreements, Rayzon and Navitas will each integrate Caelux's "energy-producing solar glass" — a perovskite-coated front glass — with their own n-type TOPCon module technology to produce hybrid tandem panels. Caelux designs the perovskite layer to sit on top of a conventional silicon cell, capturing part of the solar spectrum that silicon alone converts less efficiently.

The partners are targeting module efficiencies of up to 28%, comfortably above the roughly 22–24% typical of mainstream commercial silicon panels today. Commercial production is targeted for 2028, giving both manufacturers a runway to qualify the technology, build lines and secure supply.

Why perovskite tandems matter

Single-junction silicon cells are approaching a practical efficiency ceiling of around 27% in the lab, and far less in mass production. Stacking a perovskite layer on silicon lets a module harvest more of the spectrum, pushing the theoretical ceiling well past 40% and offering a credible path to cheaper electricity per watt without needing more land or racking.

Perovskite-silicon tandems have dominated recent solar efficiency records, but moving them from laboratory champions to bankable, field-durable products has been the industry's central challenge. Caelux's glass-integrated approach is one of several commercialisation strategies aiming to bolt perovskite performance onto the existing silicon supply chain rather than replace it.

A domestic-manufacturing angle

The deals matter for India beyond the efficiency numbers. New Delhi has built out large TOPCon cell and module capacity under schemes such as the Approved List of Models and Manufacturers and production-linked incentives, but most of that capacity produces commodity panels that compete largely on price. Anchoring an advanced tandem line domestically would give Indian manufacturers a higher-value product and a foothold in a technology where global leadership is still up for grabs.

It also fits a broader pattern in 2026 of Indian solar firms signing technology partnerships to move up the value chain — whether in cells, wafers or advanced materials — as the country pushes toward its renewable-capacity goals.

The road ahead

The 2028 production target is ambitious. Tandem modules must still prove long-term stability — perovskites are historically sensitive to moisture, heat and ultraviolet exposure — and manufacturers will have to demonstrate that the tandem premium survives real-world warranties and financing due diligence. Yield, cost and bankability, not just peak efficiency, will decide whether 10 GW of announced intent becomes installed capacity.

For now, the Rayzon and Navitas agreements put two Indian names on the tandem map and signal that the country's solar ambitions are starting to track the technology frontier, not just chase volume.

Sources

• pv magazine India: https://www.pv-magazine-india.com/2026/07/23/rayzon-solar-navitas-partner-us-based-caelux-to-develop-10-gw-of-perovskite-silicon-tandem-modules-in-india/
• pv magazine (global): https://www.pv-magazine.com/2026/07/24/rayzon-solar-navitas-partner-us-based-caelux-to-develop-10-gw-of-perovskite-silicon-tandem-modules-in-india/
• PV Tech: https://www.pv-tech.org/caelux-links-up-with-rayzon-navitas-on-10gw-perovskite-pv-commercialisation-deals-in-india/
• TaiyangNews: https://taiyangnews.info/business/caelux-rayzon-navitas-target-10-gw-tandem-solar-india