Proceedings of Asia-Pacific Conference on Perovskite, Organic Photovoltaics&Optoelectronics (IPEROP25)
Publication date: 17th October 2024
The growth of high quality perovskite film is critical for the realization of high performance devices. However, currently, the growth kinetics of perovskite film remains to be elusive. In this talk, I will present our recent work of controlling perovskite growth kinetics by controlling precursor supersaturation, surface energy regulation, coordination number optimization, and reagent variation etc. We developed a supersaturation controlled strategy to balance the nucleation and crystal growth speeds. By this strategy, we are able to find an ideal supersaturation region to realize a balance of nucleation and crystal growth, which yields highly crystallized perovskite films with micrometer-scale grains. A propeller‐shaped halogenated tertiary ammonium is synthesized, showing high binding energy on the perovskite surface and large steric hindrance. This molecule can significantly reduce the barrier of high surface energy that suppresses the growth of the α‐phase CsxFA1−xPbI3 structure. We explored formamidine acetate (FAAc) and ammonium iodide (NH4I) to replace the generally used formamidinium iodide (FAI) in the growth of a tin perovskite film. This triple reagent (FAAc + NH4I + SnI2) method prolongs the reaction path for the growth of the tin perovskite film. It impedes the growth of a three-dimensional (3D) perovskite structure at room temperature while having less impact on the growth of a low-dimensional structure. As a result, the low-dimensional structure formed at room temperature serves as a seed structure for 3D structure growth in subsequent annealing.