With the aid of graphene, recent research breakthroughs are addressing the “short lifespan” challenge of photovoltaic cells.
A persistent challenge in the photovoltaic industry is extending the lifespan of perovskite solar cells. These cells are known for their high conversion efficiency, low cost, flexibility, and lightweight properties, making them a promising new technology in the solar market. However, perovskite materials are prone to chemical decomposition and structural degradation, which significantly diminishes their efficiency.
On March 7, 2025, a team from East China University of Science and Technology, led by Professors Hou Yu and Yang Shuang, published their latest findings in the journal Science. This research identifies a crucial mechanism behind the instability of new photovoltaic materials—specifically, the photomechanical-induced degradation effect. The team proposed a novel method that incorporates graphene-polymer mechanically enhanced perovskite materials, achieving a record operational lifespan of 3,670 hours under standard sunlight and high temperatures. This advancement offers a fresh solution for the industrial application of perovskite solar cells.
The research team emphasized that for perovskite materials, which are sensitive to light, this discovery is significant as it uncovers an unknown key factor causing the degradation of photovoltaic performance—referred to as “photomechanical effects.” Professor Hou Yu explained, “Under sunlight, perovskite materials exhibit a notable photostrictive effect, expanding by more than 1%. This expansion compresses the perovskite crystals, creating localized stress near the grain boundaries, which accelerates defect formation and leads to performance loss in perovskite cells.” Thus, this discovery paves the way for overcoming stability challenges and advancing the industrial production and application of perovskite devices.
This breakthrough is largely attributed to the use of graphene. Yang Shuang explained to First Financial that compared to silicon solar cells, perovskite solar cells offer advantages such as high conversion efficiency, low cost, flexibility, and lightweight properties, making them vital in addressing energy and environmental issues. However, device instability remains the primary challenge hindering their industrial development. Graphene, with an extraordinarily high modulus—50 to 100 times that of perovskite materials—boasts uniform density, resistance to mechanical fatigue, and chemical stability. The researchers contemplated whether graphene could be used to enhance the stability of perovskite materials.
After multiple trials, the team discovered that assembling a single layer of graphene onto the surface of the perovskite film enabled high uniformity and multifunctional integration, resulting in a novel perovskite solar cell device. Professor Hou noted that thanks to the mechanical properties of graphene and the coupling effects of polymers, the modulus and hardness of the perovskite film were doubled, significantly constraining the dynamic lattice expansion under illumination conditions.
The structure of the perovskite solar cell consists of five layers, including conductive glass, a hole transport layer, the perovskite layer, an electron transport layer, and a metal electrode. To improve the stability of the perovskite material at its core, scientists have typically tried modifying the perovskite composition and crystallinity or designing the molecular structure of the perovskite surface, but with limited success. By adding graphene, the graphene-polymer bilayer structure reduced the lattice deformation rate from +0.31% to +0.08%, effectively minimizing the damage caused by expansion near the grain boundaries.
The research, titled “Graphene-polymer reinforcement of perovskite lattices for durable solar cells,” lists East China University of Science and Technology as the sole corresponding institution. Professors Hou Yu and Yang Shuang are the corresponding authors, while the first author is Li Qing, a doctoral student from the Materials Science department. This research received support from the National Natural Science Foundation and the Shanghai Municipal Basic Research Project, among others.
