Kinetic Control of Perovskite Thin-Film Morphology and Application in Printable Light-Emitting Diodes

Highly luminescent methylammonium lead bromide (CH₃NH₃PbBr₃) perovskite fibrous microstructure thin films have been fabricated using a perylene-3,4,9,10-tetracarboxylic dianhydride-containing antisolvent-mediated single-step fabrication method. Confocal microscopy of these thin films reveals homogeneous emission over the entire area, in contrast to the localized emission from the thin films fabricated by conventional methods. The antisolvent treatment produces pinhole-free, mazelike morphology with high photoluminescence yield. These films were incorporated as the emissive layer in thin-film light emitting diodes (LEDs), made using a low-temperature meltable and processable alloy as cathode. These LEDs gave luminescence efficiency of up to 50 Cd/m². The proposed LED structure highlights the prospects of using low-temperature roll-to-roll processing for manufacturing perovskite-based solar cells and LEDs.