Efficient Quantum Dot Light-Emitting Diodes Based on Trioctylphosphine Oxide-Passivated Organometallic Halide Perovskites.

Metal halide perovskite quantum dots (QDs) have attracted significant research interest in the next-generation display and solid illumination fields due to their excellent optical properties of high photoluminescence quantum efficiency, high color purity, obvious quantum confinement effect, and large exciton binding energy. A large amount of surface defects and nonradiative recombination induced by these defects are considered as major problems to be resolved urgently for practical applications of perovskite QDs in high-efficiency light-emitting diodes (LEDs). Herein, we report an efficient passivation of green perovskite QD CH3NH3PbBr3 with trioctylphosphine oxide (TOPO). By simply adding the appropriate amount of TOPO into the nonpolar toluene solvent to synthesize CH3NH3PbBr3 QDs, the surface defects of these as-synthesized perovskite QDs are obviously reduced, along with an increased photoluminescence lifetime and suppressed nonradiative recombination. Further investigation indicates that electronegat...