Pure-Blue Emitting Face-Down-Oriented Perovskite Nanoplatelets for Light-Emitting Diodes

Pure-blue lead trihalide perovskite nanoplatelets (PeNPLs) exhibit anisotropy and polarized transition dipole moments owing to their morphology, which is beneficial for optoelectronic devices. However, studies focusing on the lateral size of PeNPLs and their orientation (“face down” and “edge up”) have not demonstrated these advantages. In this study, large lateral-size PeNPLs showed strong face-down orientation and superior optical properties, leading to the improved performance of light-emitting diodes (LEDs). These findings provide valuable insights and suggest a promising strategy for the development of high-performance pure-blue LEDs using PeNPLs.