UV-Green Emission from Organolead Bromide Perovskite Nanocrystals

Ultraviolet (UV)-green emitting MAPbBr 3 nanocrystals were synthesized at room temperature, employing a cost-effective solution-based method. The size control of nanocrystals was achieved through varying ligand and solute concentrations, which resulted in a tunable band gap and emission spectrum. The growth mechanism as well as the effect of ligand concentration on the structural and optical properties were studied in detail. The excitation spectra extended from the blue to UV region. This indicates that these perovskites are promising photon down conversion materials, which can combine with III-nitride UV/blue light-emitting diodes (LEDs) to emit white light. This work may bring III-nitride-based white LEDs one step closer to widespread adoption in general illumination market because the large emission range that has been produced with the ligand-assisted reprecipitation process is an important milestone in the path to justifying commercialization.