Synthesis of Hybrid Tin-Based Perovskite Microcrystals for LED Applications.

Considerable focus on tin-based perovskites lies on substitution to leadhalide perovskites for the fabrication of eco-friendly optoelectronic devices. The major concern related to tin-based perovskite devices are mainly the stability and the efficiency. However, thinking on the final commercialization scope, other considerations such as precursor stability and cost are major factors to carry about. In this regard, this work presents a robust and facile synthesis of 2D ASnX (A = 4-fluorophenethylammonium(4-FPEA); X = I, Br, I/Br) and 3D FASnI perovskite microcrystals following a developed synthesis strategy with low-cost starting materials. In this developed methodology, acetic acid is used as a solvent, which helps to protect from water by making a hydrophobic network over the perovskite surface, and hence provides sufficient ambient and long-term inert atmosphere stability of the microcrystals. Further, the microcrystals are recrystallized in thin films for LED application, allowing the fabrication of orange, near-infrared and purered emitting LEDs. The two-step recrystallized devices show better performance and stability in comparison to the reference devices made by using commercial precursors. Importantly, the developed synthesis methodology is defined as a generic method for the preparation of varieties of hybrid tin-based perovskites microcrystals and application in optoelectronic devices.