Metal halide perovskites have emerged as leading candidates for next-generation optoelectronic materials owing to their remarkable optical tunability and processability. However, achieving phase-stable and morphologically uniform iodide-based perovskite nanoplatelets (PeNPLs) has remained a major challenge due to thermodynamic instability and ligand detachment under ambient conditions.
In a new paper published in Light: Science & Applications , a team of scientists, led by Professor Robert L. Z. Hoye, Dr. Junzhi Ye and Dr. Woo Hyeon Jeong from the Inorganic Chemistry Laboratory, University of Oxford, along with Professor Bo Ram Lee from School of Advanced Materials Science and Engineering, Sungkyunkwan University in South Korea, and co-workers have report a formamidinium (FA)-alloying strategy that enhances the stability of CsPbI 3 PeNPLs. FA incorporation not only improves the bulk thermodynamic stability to suppress degradation to the non-photoactive yellow phase, it also strengthens surface ligand binding, thus reducing environmental degradation. Through compositional engineering, the Cs/FA-alloyed PeNPLs self-assemble into highly oriented superlattices with improved vertical orientation, thus improving the degree of linear polarization of light emitted.
This integrated approach of compositional tuning and surface modulation demonstrates a practical route for stabilizing strongly confined PeNPLs while maintaining excellent optical anisotropy. The findings not only address the long-term stability bottleneck of red-emitting iodide-based PeNPLs but also pave the way for the realization of efficient and polarized light-emitting devices and next-generation photonic displays.
Light Science & Applications
Enhanced stability and linearly polarized emission from CsPbI3 perovskite nanoplatelets through A-site cation engineering