Effects of Anti-solvent Wash on Solvent Engineered Methylammonium Lead Bromide Perovskites for Light-emitting Diode Applications

Organometal halide perovskites have shown promise for optoelectronic devices such as solar cells and light-emitting diodes (LEDs). Perovskite optoelectronic devices offer an advantage over traditional semiconductor devices due to their potential to be made at low cost using solution processing while maintaining excellent electronic properties. Currently, the efficiencies of LEDs made using perovskites are still lacking compared to organic LEDs and inorganic LEDs. The role of fabrication on crystal formation for bromide perovskite systems is still not fully understood. To further this understanding, this work compares the effects of different anti-solvents when creating solvent engineered MAPbBr₃ films with a focus on LED applications. The crystal structure of the films was confirmed via XRD. The film surface morphology was characterized using AFM; SEM was used to identify grain size and internal morphology. Photoluminescence was used to compare the different anti-solvents. Photothermal deflection spectroscopy was used to compare trap densities and general order within the films. Finally, LEDs were made using films of each anti-solvent wash, demonstrating the effect of the antisolvent on device performance.