Ordered dimensional distribution of 2D/3D tin perovskites for efficient photovoltaics

Tin perovskites, with the advantages of low toxicity and superior optoelectronic properties, are regarded as one of the most promising light absorbers for application in next-generation photovoltaic technologies. Due to the passivation and protection effect via introducing low dimensional phases, two-dimensional/three-dimensional (2D/3D) tin perovskite films show great potential for achieving high-performance solar cells. However, the relatively strong Lewis acidity of Sn2+ leads to rapid crystallization and severe coupling of different dimensional phase structures, therefore resulting in random dimensional distribution for increased charge transfer barrier and inferior charge transport. To solve this, this project proposes an innovative strategy of ""slow-release effect induced sequential crystallization"" by using tridentate chelating agents. With this type of molecules, the strongly anchored Sn2+ could trigger slow-release effect, making the phases with different dimensionalities self-assemble in a designed and ordered way, thus slowing down the crystallization process and decoupling the formation of different dimensional phases. The objectives are to obtain high-quality tin perovskite films with in-situ growth of orderly distributed 2D-3D structure from top to bottom, thus to realize efficient tin perovskite solar cells (PSCs). This project will not only present innovative ideas and unique mechanisms for realizing sequential crystallization, but also provide effective approaches for developing efficient and stable mixed dimensional tin PSCs. Therefore, it will pave a way for achieving environmentally-friendly photovoltaics with high performance, thus benefiting the utilization of renewable energy to promote the sustainable development. Combining my experience on crystallization regulation with theoretical and technical foundations on photovoltaic devices of the host, Marie-Curie fellowship will support me to become an outstanding principal investigator in future.""