In November 2025, under the leadership of Professor Qi Yabing, the PuYuan School of Future Technology and Zhangjiang Advanced Research Institute at Shanghai Jiao Tong University teamed up with renowned institutions, including the Okinawa Institute of Science and Technology Graduate University and Hefei University of Technology. Together, they achieved a significant technological breakthrough in the realm of perovskite solar cells.

The research tackled three major challenges that have long plagued the traditional hole transport layer material spiro - OMeTAD. Firstly, lithium - ion migration leads to poor device stability. Secondly, the doping process, which relies on air oxidation, is difficult to control. Thirdly, the additive tBP is highly corrosive and can damage perovskite structures.

To overcome these issues, an innovative solution was put forward: the Light - Accelerated Oxidation Doping (LODT) strategy. This strategy makes use of ammonium salt - based TFSI dopants. Under illumination, these dopants release protons, enabling efficient oxidation of spiro - OMeTAD. At the same time, THF is used as a partial substitute for tBP as a solvent, which helps prevent damage to the perovskite layer.

The research team also constructed a dual - TFSI additive synergistic system. On one hand, KTFSI is introduced into the perovskite precursor to regulate the crystallization process. This increases the grain size from less than 500 nanometers to over 1 micrometer and reduces the defect density. On the other hand, OATFSI is applied for passivation treatment on the perovskite surface. This forms a thermally stable 2D perovskite layer and increases the water contact angle from 2.9° to 66.1°, significantly enhancing the device's resistance to moisture.

Experimental results were highly promising. A 12.83 cm² perovskite solar module developed based on this strategy achieved a certified photoelectric conversion efficiency of 20.95%. This places it among the top performers for lithium - free spiro - OMeTAD hole transport layer modules. Moreover, after 700 hours of continuous operation, the unencapsulated device still retained 93% of its initial efficiency, demonstrating excellent long - term stability.

This technology is well - suited for scalable fabrication processes like blade coating. During module scaling, there is minimal efficiency loss, providing a viable and expandable technological pathway for the commercialization of perovskite photovoltaic technology.