30%‑Plus Tandem Cell Breaks Efficiency Record

Record 30.2% Efficiency Confirmed

The University of Sydney team has demonstrated a two‑terminal perovskite‑silicon tandem solar cell that converts 30.2 % of sunlight into electricity – one of the highest certified efficiencies for a 10 cm² monolithic device. The result was independently verified by CSIRO’s PV Performance Lab, confirming the breakthrough beyond the single‑junction silicon limit of ~29.4 %.

Why Size Matters and How the Cell Works

Scaling perovskite layers from 1 cm² to 10 cm² required a uniform hole‑selective layer, which the researchers engineered to enable reproducible solution‑processed perovskite deposition across a larger area. The bottom junction is a heterojunction silicon cell, while the top perovskite absorber captures high‑energy photons, allowing the two sub‑cells to operate near their optimal voltage‑current points. This architecture delivers the combined voltage needed for a 2‑terminal (2T) monolithic stack, eliminating the need for separate wiring.

Global Race to 30%‑Plus Tandems

Sydney’s achievement puts the team among a handful of groups that have reported >30 % efficiencies on larger‑area tandems, including Longi, JA Solar, Trina Solar (with NUS), and a consortium led by Suzhou Maxwell and the University of Oxford. Earlier this year, a 1 cm² perovskite‑silicon tandem reached 30 % efficiency and was certified by the U.S. National Renewable Energy Laboratory (NREL) Science Daily. Other coverage has highlighted similar progress, emphasizing that the 30 % threshold is now seen as a realistic commercial target Renewable Energy World.

What This Means for Israel’s Solar Future

Israel’s rooftop market typically installs ~10 kWp residential systems that, with conventional silicon panels (~20 % efficiency), generate about 17 000 kWh per year in the central region (≈1700 kWh/kWp·yr). A higher‑efficiency tandem module could increase that production proportionally, potentially adding a substantial amount of energy each year. At the residential feed‑in tariff of ₪0.48 /kWh, the extra generation would raise revenue and could shorten the simple payback period compared with current silicon‑based installations. The higher efficiency also reduces the roof area needed for the same output, easing structural constraints on older buildings.

Outlook and Next Steps

The Sydney team says the breakthrough “provides a good foundation for further area scaling of perovskite layer for improved electrical performance and stability.” The next milestones are to push cell areas beyond 10 cm², demonstrate long‑term (>1 year) stability, and integrate the tandems into commercial modules. If those hurdles are cleared, Israeli installers could soon offer higher‑output panels that lower balance‑of‑system costs and help the country move toward its 30 % renewable electricity target for 2030.

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Key take‑aways

• 30.2 % certified efficiency on a 10 cm² perovskite‑silicon tandem (among the highest for that size).
• Uniform hole‑selective layer solved the scaling challenge for solution‑processed perovskite.
• The result puts Australia among a select global group achieving >30 % on larger‑area tandems.
• A typical Israeli 10 kWp home system yields about 17 000 kWh/yr; higher‑efficiency tandems could raise that output and improve payback.
• Commercial rollout will depend on durability testing and module‑scale manufacturing.

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