Researchers at NTU Singapore have developed ultra-thin perovskite solar cells that are 50 times thinner than conventional designs using a vacuum-based thermal evaporation process. These cells can generate energy under diffuse light and are semi-transparent, making them suitable for integration into building windows and facades. The technology offers advantages such as simple manufacturing processes, low temperatures, and the ability to absorb specific wavelengths while remaining transparent. The cells have shown promising conversion efficiencies and could potentially generate hundreds of MWh per year when installed on glass-facade buildings. The researchers are working on scaling up production and exploring applications in sustainable architecture, with a focus on enhancing the stability, durability, and scalability of the thermal evaporation process for potential commercialization.