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In the field of solar cells, perovskite solar cells have emerged as a promising alternative to traditional silicon-based cells due to their high conversion efficiency, low cost, flexibility, and lightweight nature. These advantages make perovskite cells a cutting-edge photovoltaic technology with significant potential for addressing energy and environmental challenges. However, their instability remains a major obstacle to commercialization.
On March 7, a research team from the School of Materials Science and Engineering at East China University of Science and Technology (ECUST), led by Professors Hou Yu and Yang Shuang, published their latest findings in the prestigious journal Science. Their study reveals a key instability mechanism in perovskite photovoltaics—“photo-mechanical” degradation—and introduces a novel method using graphene-polymer mechanical reinforcement to enhance perovskite stability. The resulting solar cells achieved a record-breaking operational lifespan, setting a new global benchmark for similar experimental devices. This discovery brings humanity one step closer to cheaper, thinner, and more durable solar panels.
Perovskite solar cells, often called the “light of the future,” not only generate electricity like traditional silicon-based cells but can also be made ultra-thin, flexible, and even integrated into clothing or windows. However, their short lifespan has been a long-standing challenge, as exposure to sunlight quickly degrades their performance, rendering them unsuitable for practical use.
Surprisingly, perovskite cells exhibit a paradoxical trait—they are highly sensitive to light, despite being designed to harness solar energy. As a soft crystalline material, perovskite is vulnerable to environmental factors such as moisture, oxygen, heat, and electric fields, all of which contribute to chemical degradation and structural deterioration, ultimately reducing efficiency.
Professor Yang Shuang explained that perovskite solar cells are composed of five layers: conductive glass, hole transport layer, perovskite, electron transport layer, and metal electrodes. Previous attempts to enhance perovskite stability focused on modifying its chemical composition or surface molecular structure, but these approaches have yet to meet practical application standards. The discovery of the "photo-mechanical degradation effect" provides a new perspective on material degradation and offers fresh insights for improving long-term stability.
After numerous experiments, the researchers found that a polymer similar to plastic—poly(methyl methacrylate) (PMMA)—could act as an intermediary. By leveraging interfacial coupling, they successfully assembled monolayer graphene onto the perovskite film, achieving high uniformity and multifunctional integration. This breakthrough led to the development of a new generation of perovskite solar cells.
Professor Hou Yu explained that their study identified localized dynamic stress within perovskite materials as a critical factor in degradation, which they termed the “photo-mechanical degradation effect.” Under sunlight, perovskite materials exhibit significant photostrictive effects, expanding by more than 1%, which generates internal stress at the grain boundaries. This accelerates defect formation and performance loss in the cells.
Thanks to the superior mechanical properties of graphene and the coupling effect of polymers, the perovskite film’s modulus and hardness were enhanced twofold. This significantly mitigated the material’s dynamic expansion and contraction under light exposure. The graphene-polymer dual-layer structure reduced lattice deformation from +0.31% to +0.08%, minimizing damage caused by expansion and ensuring long-term stability under sunlight, high temperatures, and vacuum conditions.
Beyond providing a practical solution, this research has also reshaped scientific understanding. Over the past decade, global researchers have primarily focused on improving perovskite compositions, but the ECUST team was the first to identify “physical damage” as a hidden degradation factor. Experts believe this work redefines stability enhancement strategies for perovskite solar technology.
Professor Hou Yu emphasized that this study’s most significant contribution is uncovering the previously unknown “photo-mechanical effect” as a key cause of photovoltaic performance degradation. This fundamental understanding of dynamic structural damage in perovskite films provides a new strategy for overcoming stability bottlenecks and accelerating industrial production and application of perovskite solar cells.
Cost analysis indicates that perovskite solar cells can be produced at just one-third the cost of silicon-based cells, with additional room for efficiency improvements.
With this stability breakthrough, what was once an experimental "technology of the future" is now rapidly moving toward widespread adoption, offering a "China solution" for the global transition to green energy.
On March 7, a research team from the School of Materials Science and Engineering at East China University of Science and Technology (ECUST), led by Professors Hou Yu and Yang Shuang, published their latest findings in the prestigious journal Science. Their study reveals a key instability mechanism in perovskite photovoltaics—“photo-mechanical” degradation—and introduces a novel method using graphene-polymer mechanical reinforcement to enhance perovskite stability. The resulting solar cells achieved a record-breaking operational lifespan, setting a new global benchmark for similar experimental devices. This discovery brings humanity one step closer to cheaper, thinner, and more durable solar panels.
Key Research Findings
The research team successfully developed perovskite solar cells with improved longevity, achieving a record-breaking t97 (maintaining 97% efficiency) operational lifespan of 3,670 hours (approximately 153 days) under standard sunlight and high-temperature conditions. This marks a major step forward in making perovskite solar cells viable for industrial applications.Perovskite solar cells, often called the “light of the future,” not only generate electricity like traditional silicon-based cells but can also be made ultra-thin, flexible, and even integrated into clothing or windows. However, their short lifespan has been a long-standing challenge, as exposure to sunlight quickly degrades their performance, rendering them unsuitable for practical use.
Unveiling the Mystery of Perovskite Instability
The research team discovered that perovskite materials expand and contract under sunlight, much like a balloon inflating and deflating. Over time, this mechanical stress causes internal structural damage, leading to fractures and degradation. Their findings show that perovskite materials can expand by more than 1% under light exposure, creating internal stress that weakens the crystalline structure—similar to how repeatedly folding a piece of paper eventually causes it to tear.Surprisingly, perovskite cells exhibit a paradoxical trait—they are highly sensitive to light, despite being designed to harness solar energy. As a soft crystalline material, perovskite is vulnerable to environmental factors such as moisture, oxygen, heat, and electric fields, all of which contribute to chemical degradation and structural deterioration, ultimately reducing efficiency.
Professor Yang Shuang explained that perovskite solar cells are composed of five layers: conductive glass, hole transport layer, perovskite, electron transport layer, and metal electrodes. Previous attempts to enhance perovskite stability focused on modifying its chemical composition or surface molecular structure, but these approaches have yet to meet practical application standards. The discovery of the "photo-mechanical degradation effect" provides a new perspective on material degradation and offers fresh insights for improving long-term stability.
Strengthening Perovskite with Graphene
To address perovskite’s inherent fragility, the team turned to graphene, a two-dimensional material that has earned Nobel Prize recognition. Graphene boasts extraordinary mechanical strength—50 to 100 times higher than perovskite—while also being dense, resistant to mechanical fatigue, and chemically stable. The challenge, however, lies in integrating graphene with perovskite, as the two materials are inherently incompatible.After numerous experiments, the researchers found that a polymer similar to plastic—poly(methyl methacrylate) (PMMA)—could act as an intermediary. By leveraging interfacial coupling, they successfully assembled monolayer graphene onto the perovskite film, achieving high uniformity and multifunctional integration. This breakthrough led to the development of a new generation of perovskite solar cells.
Professor Hou Yu explained that their study identified localized dynamic stress within perovskite materials as a critical factor in degradation, which they termed the “photo-mechanical degradation effect.” Under sunlight, perovskite materials exhibit significant photostrictive effects, expanding by more than 1%, which generates internal stress at the grain boundaries. This accelerates defect formation and performance loss in the cells.
A "Bulletproof Vest" for Perovskite Cells
To counteract this degradation, the team devised a protective layer akin to a "bulletproof vest" for perovskite materials. Using graphene—one of the world’s strongest materials—combined with a specialized transparent polymer, they created an ultra-thin protective layer measuring just one ten-thousandth the thickness of a human hair. Laboratory tests confirmed that this protective layer doubled the material’s resistance to stress, reducing its expansion rate from 0.31% to just 0.08%, akin to adding shock-absorbing packaging to fragile goods.Thanks to the superior mechanical properties of graphene and the coupling effect of polymers, the perovskite film’s modulus and hardness were enhanced twofold. This significantly mitigated the material’s dynamic expansion and contraction under light exposure. The graphene-polymer dual-layer structure reduced lattice deformation from +0.31% to +0.08%, minimizing damage caused by expansion and ensuring long-term stability under sunlight, high temperatures, and vacuum conditions.
Record-Breaking Performance
After extensive testing, solar cells equipped with this protective layer set a new record: maintaining 97% efficiency after operating continuously for 3,670 hours in simulated real-world conditions of intense light and high temperatures. This is the longest stable operation reported for perovskite solar cells, bringing them closer to real-world application.Beyond providing a practical solution, this research has also reshaped scientific understanding. Over the past decade, global researchers have primarily focused on improving perovskite compositions, but the ECUST team was the first to identify “physical damage” as a hidden degradation factor. Experts believe this work redefines stability enhancement strategies for perovskite solar technology.
Professor Hou Yu emphasized that this study’s most significant contribution is uncovering the previously unknown “photo-mechanical effect” as a key cause of photovoltaic performance degradation. This fundamental understanding of dynamic structural damage in perovskite films provides a new strategy for overcoming stability bottlenecks and accelerating industrial production and application of perovskite solar cells.
Industry Applications and Future Prospects
The research team has already begun collaborating with industry partners to test this technology in real-world applications. If successfully mass-produced, this breakthrough could revolutionize the energy sector. Potential applications include power-generating glass for building exteriors, foldable outdoor solar chargers, and ultra-thin solar films capable of charging smartphones.Cost analysis indicates that perovskite solar cells can be produced at just one-third the cost of silicon-based cells, with additional room for efficiency improvements.
With this stability breakthrough, what was once an experimental "technology of the future" is now rapidly moving toward widespread adoption, offering a "China solution" for the global transition to green energy.
