Self-Healing Solar Cells Could Reduce Production Costs
The cosmetics industry often warns that sun damage is detrimental to skin, and until now, the photovoltaic sector shared similar concerns regarding solar panels. However, groundbreaking research from the University of New South Wales (UNSW) reveals that much of the harm inflicted by ultraviolet rays on solar cells is often reversible.
Remarkably, it appears that solar cells possess the ability to heal themselves. This research is promising as it could not only reduce the costs associated with manufacturing solar modules but also enhance their efficiency, as it enables researchers and manufacturers to observe the impact of UV radiation on solar cells in real time while they operate.
A Novel Technique for Examination
The investigation by UNSW has introduced a technique using ultraviolet Raman spectroscopy, which involves lasers that scatter light to uncover molecular vibrations within a material. This innovative approach allows researchers, including lead author Ziheng Liu, to witness changes within the solar cell without the need for physical destruction or reliance on power output readings. “This method functions like a camera. Rather than just gauging the power output of the cell, we can actually observe the material’s transformation in real time,” Liu elaborated in a statement.
Understanding Degradation and Recovery
Previously, solar cells were evaluated for their resilience to UV damage during manufacturing through intense exposure that simulated 2000 hours of sunlight, followed by a process of dismantling the cell to examine the effects, which could take days to weeks. This new UNSW research demonstrates that the “normal” sunlight in everyday scenarios can facilitate the healing of UV-inflicted damage, particularly observed in TOPCon solar cells.
Solar cells operate based on hydrogen bonding with silicon to maximise efficiency, yet UV radiation disrupts these bonds. Contemporary cells incorporate a buffer layer of magnesium or aluminium oxides, but the findings suggest that it may not be necessary to maintain this layer as thick as current practices dictate. Liu indicated that just ten to twenty minutes of normal sunlight can allow these vital bonds to reform, suggesting that manufacturers might be overestimating irreversible damage and hence unnecessarily enhancing their panels.
The research also highlighted that different types of solar cells exhibit varying degrees of reversibility, with a specific focus on TOPCon technology, which is anticipated to become predominant in the upcoming years. This development implies that not only can these solar panels repair UV damage autonomously, but manufacturers could also simplify their designs, using a thicker aluminium oxide film alongside a thinner silicon-nitrogen layer.
