Ligand-mediated synthesis of chemically tailored two-dimensional all-inorganic perovskite nanoplatelets under ambient conditions

All-inorganic halide perovskite nanocrystals (NCs) offer impressive optoelectronic properties for light harvesting, energy conversion, and photoredox applications, with two-dimensional (2D) perovskite NCs further increasing these prospects due to their improved photoluminescence (PL) tuneability, impressive color purity, high in-plane charge transport, and large lateral dimensions which is advantageous for device integration. However, the synthesis of 2D perovskites is still challenging, especially toward large-scale applications. In this study, through the control of surface ligand composition and concentration of a mixture of short (octanoic acid and octylamine, 8-carbon chain) and long (oleic acid and oleylamine, 18-carbon chain) ligands, we have developed an extremely facile ligand-mediated synthesis of 2D CsPbX3 (X = Cl, Br, or mixture thereof) nanoplatelets (NPLs) at room temperature in an open vessel. In addition, the developed method is highly versatile and can be applied to synthesize Mn-doped CsPbX3 NPLs, showing a systematic increase in the total PL quantum yield (QY) and the Mn-dopant emission around 600 nm with increasing Mn and Cl concentrations. The reaction occurs in toluene by the introduction of CsX, PbX2, and MnX2 precursors under ambient conditions, which requires no harsh acids, avoids excessive lead waste, little thermal energy input, and is potentially scalable toward industrial applications.

Automated summary

The study presents a facile ligand-mediated synthesis method for preparing high-quality 2D CsPbX3 nanoplatelets with impressive optoelectronic properties. This versatile method can also be used to synthesize Mn-doped CsPbX3 nanoplatelets, showing increased emission efficiency with higher concentrations of Mn and Cl. The reaction, carried out in toluene under ambient conditions, offers a promising approach for industrial applications due to its simplicity and scalability.