Functionalized PFN-X (X = Cl, Br, or I) for Balanced Charge Carriers of Highly Efficient Blue Light-Emitting Diodes.
Yun Seop ShinYung Jin YoonJungwoo HeoSuhee SongJae Won KimSong Yi ParkHye Won ChoGi-Hwan KimJin Young KimPublished in: ACS applied materials & interfaces (2020)
All-inorganic perovskite nanocrystals (PeNCs), CsPbX3 (X = Cl, Br, or I), have been considered as one of the prospective emissive materials for display applications, which showed superior photoluminescence quantum yield and high color purity with narrow spectral line width. Recently, high-performance green and red perovskite light-emitting diodes (PeLEDs) were introduced; however, the efficiency of blue PeLEDs still lagged owing to PeNCs' deep HOMO energy level (∼6.0 eV), which is in discord with the adjacent organic interlayer. In this work, we demonstrated an interfacial engineering strategy with conjugated polyelectrolytes, functionalized PFN (poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]) with halide anions, between the hole injection layer and PeNCs. By introducing PFN-X (X = Cl, Br, or I), they exhibit well-balanced charge carriers and resultant effective radiative recombination in the PeNC layer with reduced hole injection barrier and electron blocking behavior. Among them, in particular, the PFN-Cl-treated PeLEDs display a maximum external quantum efficiency of 1.34% at 470 nm electroluminescence emission with enhanced spectral operating stability.
Keyphrases
- solar cells
- highly efficient
- light emitting
- quantum dots
- energy transfer
- ionic liquid
- perovskite solar cells
- optical coherence tomography
- molecular dynamics
- photodynamic therapy
- room temperature
- ultrasound guided
- dna damage
- water soluble
- computed tomography
- dna repair
- mass spectrometry
- dual energy
- oxidative stress
- molecular dynamics simulations
- newly diagnosed
- monte carlo
- liquid chromatography