A5083361113- Perovskite Materials and Applications
- Organic Light-Emitting Diodes Research
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Organic Electronics and Photovoltaics
Ulsan National Institute of Science and Technology
2018-2023
Abstract Metal halide perovskites (MHPs) have emerged as promising materials for light‐emitting diodes owing to their narrow emission spectrum and wide range of color tunability. However, the low exciton binding energy in MHPs leads a competition between trap‐mediated nonradiative recombination bimolecular radiative recombination. Here, efficient stable green emissive perovskite (PeLEDs) with an external quantum efficiency 14.6% are demonstrated through compositional, dimensional,...
Further optimization of perovskite light-emitting diodes (PeLEDs) is impeded by crystal deformation caused residual stress and defect formation with subsequent non-radiative recombination. Molecular additives for passivation are widely studied; however, the majority have insulating properties that hinder charge injection transport. Herein, highly efficient green-emitting PeLEDs reported introducing semiconducting molecular (Fl-OEGA Fl-C8A). Transmission electron microscopy shows conjugated...
A series of anionic conjugated polyelectrolytes (CPEs) is synthesized based on poly(fluorene-co-phenylene) by varying the side-chain ionic density from two to six per repeat units (MPS2-TMA, MPS4-TMA, and MPS6-TMA). The effect MPS2, 4, 6-TMA as interlayers top a hole-extraction layer poly(bis(4-phenyl)-2,4,6-trimethylphenylamine (PTAA) investigated in inverted perovskite solar cells (PeSCs). Owing improved wettability perovskites hydrophobic PTAA with CPEs, PeSCs CPE demonstrate...
Metal halide perovskites (MHPs) have attracted significant attention as light-emitting materials owing to their high color purities and tunabilities. A key issue in perovskite diodes (PeLEDs) is the fabrication of an optimal charge transport layer (CTL), which has desirable energy levels for efficient injection while blocking opposite charges enabling growth with reduced interfacial defects. Herein, two poly(fluorene-phenylene)-based anionic conjugated polyelectrolytes (CPEs) different...
A series of poly(fluorene-co-phenylene)-based anionic conjugated polyelectrolytes (CPEs) are prepared with varying sizes counterions (tetramethylammonium, tetraethylammonium, and tetrabutylammonium (TBA+)) studied as a hole-transporting layer (HTL) for sky-blue-emissive perovskite light-emitting diodes (PeLEDs). Ionic CPE HTLs improve the wettability, compatibility, nucleation crystals at interfaces, enabling highly crystalline crystal growth enhanced properties. By incorporating containing...
Abstract Metal halide perovskites have deep valence band maximums (VBMs). For example, the VBM of CsPbBr 3 is 5.8–6.3 eV. Conjugated polymers can be a potential candidate for hole transport layer because their highest occupied molecular orbital levels, but poor compatibility with hydrophilic perovskite precursor results in formation noncontinuous film. In addition, antisolvent dripping methods fabricating films cause spatially inhomogeneous nucleation, which undesirable large‐scale...
Abstract Conjugated polyelectrolytes (CPEs) with π‐delocalized main backbones and ionic pendant groups are intensively studied as interfacial layers for efficient polymer‐based optoelectronic devices (POEDs) because they facilitate facile control of charge injection/extraction barriers. Here, a simple effective method performing precise energy level adjustment is presented by employing CPEs different thicknesses various ion densities under electric poling to realize POEDs. The effects the...
Metal halide perovskites have been investigated for the next-generation light-emitting materials because of their advantages such as high photoluminescence quantum yield (PLQY), excellent color purity, and facile tunability. Recently, red- green-emissive perovskite diodes (PeLEDs) shown an external efficiency (EQE) over 20%, whereas there is still room improvement blue emissive PeLEDs. By controlling compositions chloride (Cl−) bromide (Br−), bandgap can be easily tuned emission. However,...