Room-temperature synthesis of full-component APbX3 perovskite nanocrystal inks for optoelectronic applications

Lead halide perovskite nanocrystals (PNCs) have received great research interests due to their excellent optoelectronic properties. However, high temperature, inert gas protection and insulating long-chain ligands are used during the conventional hot-injection synthesis of PNCs, which limits their practical applications. In this work, we first develop a simple and scalable polar-solvent-free method for the preparation of full-component APbX3 (A = Cs, methylammonium (MA), formamidinium (FA), X = Cl, Br, I) PNCs under ambient condition. Through an exothermic reaction between butylamine (BA) and propionic acid (PA) short ligands, the PbX2 precursors could be well dissolved without use of any polar solvent. Meanwhile, the relatively lower growth rate of PNCs in our room-temperature reaction enables us to modulate the synthetic procedure to enhance the scalability (40-fold) and achieve large-scale synthesis. The resultant short ligands passivated PNC inks are compatible with varying solution depositing technique like spray coating for large-area film. Finally, we showcase that adopting the as-prepared MAPbI3 PNC inks, a self-powered photodetector is fabricated and shows a high photoresponsivity. These results demonstrate that our ambient-condition synthetic approach can accelerate the preparation of tunable and ready-to-use PNCs towards commercial optoelectronic applications.