It’s hopeful to learn of new solar panel efficiencies continuously achieved in labs by either the solar industry or academic researchers. But as panels have become more sophisticated, a harder question has lingered beneath the headlines: will these ultra-efficient cells remain stable when they leave the lab and enter the real world? A new, clear and unexpectedly reassuring study from the University of New South Wales examined TOPCon solar cells, now the dominant silicon technology globally, and a manufacturing technique known as laser-assisted firing (LAF). LAF is already widely used because it allows manufacturers to create extremely efficient electrical contacts without damaging the delicate passivation layers that prevent energy losses. Yet concerns have persisted that these laser-treated contacts might be fragile, especially when exposed to the heat involved in module assembly or long-term operation.
The new research shows that those fears are largely misplaced and that the solar cells of today are more resilient, and even more self-correcting, than previously assumed.
What happens to advanced solar cells during manufacturing?
Before a solar panel sees daylight, its cells must endure several thermal steps, notably soldering and lamination, both of which involve heating. The authors carefully replicated these processes and measured how the cells responded.
The result was strikingly modest:
- Soldering caused no measurable performance loss.
- Lamination led to a small reduction in efficiency — around 0.29 percentage points — mainly due to a temporary drop in the fill factor (a measure of how effectively a cell converts light into usable current).
In isolation, that loss might sound concerning. But the crucial finding comes next.
Solar cells that heal themselves in sunlight
After this heat-related degradation, the researchers exposed the cells to just one minute of standard sunlight at room temperature. The efficiency fully recovered, physically. Defects activated by heat became inactive again under illumination. In practical terms, it means that normal outdoor operation reverses the damage introduced during manufacturing.
This phenomenon — sometimes described as light-induced recovery — is a powerful reminder that laboratory stress tests do not always reflect real-world behaviour. For solar deployment in cooler, high-latitude regions such as Canada or Northern Europe, this is especially encouraging: modules may experience thermal stress during production, but will spend their lives operating at moderate temperatures under regular daylight.
Even extreme heat does not spell the end
The researchers then pushed the cells far beyond normal conditions, exposing them to 450°C rapid thermal annealing — temperatures far higher than those encountered in factories or the field. As expected, performance dropped sharply, driven by changes at the metal–silicon contact interface. But again, the story does not end there.
When the laser-assisted firing step was reapplied, much of the lost performance returned. The contacts could be re-optimised, restoring electrical pathways that had been disrupted by heat. In effect, the manufacturing process itself contains the tools needed to correct thermal damage.
Why this changes how we think about solar reliability
The most important contribution of this work may be conceptual rather than numerical. The authors propose a three-state defect model, showing that many performance losses are not permanent failures, but transitions between reversible states — influenced by heat, darkness, and illumination.
This matters because reliability testing has often assumed degradation is linear and irreversible. This study shows that assumption is too simplistic for modern silicon photovoltaics.
For clean energy professionals, the implication is clear: Today’s leading solar technologies are not just efficient, but robust, forgiving, and adaptable.
Why this is especially good news for cooler climates
In northern regions, solar scepticism often centres on reliability: will advanced panels cope with long winters, thermal cycling, and variable sunlight? The research suggests so and paints and even brighter picture: TOPCon cells manufactured with laser-assisted firing are shown to tolerate thermal stress, recover naturally during operation, and maintain high performance without requiring exotic materials or fragile architectures. That combination is exactly what large-scale, sustainable deployment demands in Canada, Scandinavia, and Northern Europe.
The takeaway is quietly transformative: the solar technology already rolling off production lines is more ready for the real world than we thought.
Six recommendations for government
1. Support schemes should value reliability as well as efficiency. Procurement rules, CfD qualification, and innovation funding should reward technologies that demonstrate stable performance after realistic manufacturing and thermal stress testing.
2. Keep certification tests up to date to reflect newer cell architectures such as laser-assisted TOPCon. Governments should work with standards bodies (IEC, TÜV, etc.) to ensure testing protocols reflect:
– Modern module fabrication temperatures
– Light-soaking recovery effects
– Realistic field operating conditions
3. Fund applied manufacturing research, not just lab breakthroughs This research shows that small manufacturing steps (e.g. lamination, contact firing) can strongly affect performance. Public funding should prioritise:
– Cell-to-module (CTM) loss reduction
– Manufacturing-scale validation
– Reliability modelling under real production conditions
4. Support rapid learning loops between field data and factories. Now that we understand how degradation is reversible under sunlight, governments should support:
– Long-term field monitoring of new PV technologies
– Data-sharing frameworks between installers, manufacturers, and researchers
– Faster feedback into manufacturing optimisation
5. De-risk next-generation silicon technologies and treat TOPCon optimisation as strategic energy infrastructure by:
– Supporting pilot lines and first-of-a-kind manufacturing
– Reducing investment risk for factories adopting advanced processes (e.g. laser-assisted firing)
6. Align industrial strategy with energy transition goals, to reduce land use, material demand, and system-level costs. Supporting manufacturing improvements directly accelerates:
– Faster solar deployment
– Lower system costs
– Higher lifetime energy yield per panel
Source
Thermal stability of laser-assisted fired TOPCon solar cells: Crucial insights for module manufacturing, certification testing, and field conditions, Solar Energy Materials & Solar Cells, 2025-12-16
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