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Compared to silicon solar cells, perovskite solar cells offer advantages such as high conversion efficiency, low cost, flexibility, and light weight; they represent a new type of photovoltaic technology with great potential for application, and are significant in helping to address energy and environmental issues. However, device instability is the main challenge that hinders their industrial development. In the early hours of March 7th, Beijing time, Professor Hou Yu and Professor Yang Shuang from the Team for Clean Energy Materials and Devices at the School of Materials Science, East China University of Science and Technology, along with their colleagues, published a new research finding in Science titled “Graphene-polymer reinforcement of perovskite lattices for durable solar cells”. This study was the first to reveal the key mechanism behind a new type of photovoltaic instability – the photo-mechanically induced decomposition effect. It proposed a new method for mechanically reinforcing perovskite materials using graphene and polymers. The solar cell devices fabricated using this method achieved a new record of 3670 hours of operational life under standard sunlight conditions as well as at high temperatures. These findings will provide new solutions for the industrial application of perovskite solar cells. As a key component of photovoltaic cells, perovskite materials exhibit typical soft-lattice properties; under environmental factors such as water and oxygen, light, high temperature, and electric fields, they are prone to chemical decomposition and structural degradation, resulting in a significant drop in device efficiency. “We have found that, in addition to common factors such as water, light, heat, and electricity, the dynamic local stress within perovskite materials is an important cause of material decomposition; this is known as the photo-mechanically induced decomposition effect. ”According to Professor Hou Yu, under sunlight, perovskite materials exhibit a significant photoelastic effect, with an expansion rate of over 1%. This leads to compression between the perovskite crystals, and local stress accumulates near the grain boundaries, accelerating the formation of defects in those areas and resulting in a decline in the performance of perovskite cells. According to Hou Yu, the structure of perovskite solar cells consists of five layers, from top to bottom: conductive glass, hole transport layer, perovskite, electron transport layer, and metal electrode. To improve the stability of the perovskite material at the core, scientists have tried either to modify the composition and crystallinity of the perovskite or to design structures that control the molecular arrangement on its surface, but with little success. “The discovery of the \"photo-mechanically induced decomposition effect\" provides a new perspective for the team to understand the degradation mechanisms of perovskite materials, and offers important insights for further improving their stability.