Perovskite solar cells, known for their cost-effectiveness and high power generation per surface area, have long struggled with stability issues, outpacing the efficiency of silicon market standards. A groundbreaking study led by Prof. Dr. Antonio Abate has addressed this challenge by introducing a novel coating at the interface between the perovskite surface and the top contact layer. This innovation has not only enhanced stability but also boosted efficiency to an impressive 27%, surpassing current state-of-the-art levels.
The research, published in Nature Photonics, involved an international team of scientists from China, Italy, Switzerland, and Germany. After 1,200 hours of continuous operation under standard illumination, the efficiency of the perovskite solar cells remained unchanged, a remarkable feat. The key to this success lies in the use of a fluorinated compound that acts as a Teflon-like monomolecular film, chemically isolating the perovskite layer from the contact layer and reducing defects and losses.
This intermediate layer not only enhances the structural stability of both adjacent layers, particularly the C60 layer, but also facilitates a uniform and compact structure. Prof. Abate explains, "It's akin to the Teflon effect, where the intermediate layer forms a chemical barrier, preventing defects while maintaining electrical contact."
The experimental research, conducted by Guixiang Li, a former Ph.D. student in Prof. Abate's team, has led to significant advancements. Li, now a professor at Southeast University in Nanjing, China, continues the collaboration with teams from the École Polytechnique Fédérale de Lausanne (EPFL) and Imperial College London. The study's inverted (p-i-n) structure makes it ideal for use in tandem cells, such as those combined with silicon cells.
The idea for this innovation emerged during Prof. Abate's postdoctoral days in Henry Snaith's lab, where perovskite materials were being researched. In 2014, the efficiency was a mere 15%, declining rapidly within a few hours. Fast forward to the present, and the team has made remarkable progress, paving the way for the next generation of highly efficient and stable perovskite-based optoelectronic devices.
