A5102878261- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Semiconductor Quantum Structures and Devices
- ZnO doping and properties
- Advanced Semiconductor Detectors and Materials
- Ga2O3 and related materials
- Perovskite Materials and Applications
- Nanocluster Synthesis and Applications
- Copper-based nanomaterials and applications
- GaN-based semiconductor devices and materials
- Semiconductor Lasers and Optical Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Gas Sensing Nanomaterials and Sensors
- Solid State Laser Technologies
- Molecular Junctions and Nanostructures
- Advanced Photocatalysis Techniques
- Conducting polymers and applications
- Semiconductor materials and devices
- Tactile and Sensory Interactions
- Plasma Diagnostics and Applications
- Advanced Sensor and Energy Harvesting Materials
- Organic Light-Emitting Diodes Research
- Nanowire Synthesis and Applications
- Iron-based superconductors research
- Supramolecular Self-Assembly in Materials
University of Chicago
2023-2025
Sungkyunkwan University
2020-2024
University of South Africa
2024
Seoul National University
2015-2020
Government of the Republic of Korea
2019
Korea Institute of Science and Technology
2015-2016
Tohoku University
1999-2011
Korea Maritime and Ocean University
2003-2011
Institute for Materials Research, Tohoku University
2002-2003
Pukyong National University
2001
Abstract Establishing multi-colour patterning technology for colloidal quantum dots is critical realising high-resolution displays based on the material. Here, we report a solution-based processing method to form patterns of using light-driven ligand crosslinker, ethane-1,2-diyl bis(4-azido-2,3,5,6-tetrafluorobenzoate). The crosslinker with two azide end groups can interlock ligands neighbouring upon exposure UV, yielding chemically robust dot films. Exploiting crosslinking process,...
We investigate the operational instability of quantum dot (QD)-based light-emitting diodes (QLEDs). Spectroscopic analysis on QD emissive layer within devices in chorus with optoelectronic and electrical characteristics discloses that device efficiency QLEDs under operation is indeed deteriorated by two main mechanisms. The first luminance drop running owing to accumulation excess electrons QDs, which escalates possibility nonradiative Auger recombination processes QDs. other electron...
Colloidal Ag(In,Ga)S2 nanocrystals (AIGS NCs) with the band gap tunability by their size and composition within visible range have garnered surging interest. High absorption cross-section narrow emission linewidth of AIGS NCs make them ideally suited to address challenges Cd-free in wide-ranging photonic applications. However, shown relatively underwhelming photoluminescence quantum yield (PL QY) date, primarily because coherent heteroepitaxy has not been realized. Here, we report for...
Thick inorganic shells endow colloidal nanocrystals (NCs) with enhanced photochemical stability and suppression of photoluminescence intermittency (also known as blinking). However, the progress using thick-shell heterostructure NCs in applications has been limited due to low quantum yield (PL QY ≤ 60%) at room temperature. Here, we demonstrate CdS/CdSe/CdS seed/spherical well/shell (SQW) geometry that exhibit near-unity PL temperature blinking. In SQW NCs, lattice mismatch is diminished...
Advance in wet chemistry enables the sophisticated design of nanocrystal quantum dots (QDs) and allows unprecedented color purity brightness, promising their useful applications a variety light-emitting applications. A representative example is core/shell heterostructures, which charge carriers are effectively decoupled from structural artifacts to generate photons efficiently. Despite development widely accepted synthetic protocols for Cd- or Pb-based QDs, progress heterostructuring...
Abstract Conventional stretchable electronics that adopt a wavy design, neutral mechanical plane, and conformal contact between abiotic biotic interfaces have exhibited diverse skin‐interfaced applications. Despite such remarkable progress, the evolution of intelligent skin prosthetics is challenged by absence monolithic integration neuromorphic constituents into individual sensing actuating components. Herein, bioinspired sensory‐neuromorphic system, comprising an artificial...
Abstract Inkjet printing of colloidal quantum dots (QDs) is considered a promising technology for application in full‐color dot light‐emitting diode (QLED) displays. However, QLEDs that are inkjet printed pixel‐defining bank structure generally exhibit low performance, mainly due to the nonuniformity its QD morphology. In this study, an enhanced performance inkjet‐printing‐based pixelated achieved by introducing small amounts poly(methyl methacrylate) (PMMA) different molecular weights into...
We present multifunctional dendrimer ligands that serve as the charge injection controlling layer well adhesive at interfaces between quantum dots (QDs) and electron transport (ETL) in dot light-emitting diodes (QLEDs). Specifically, we use primary amine-functionalized (e.g., a series of poly(amidoamine) dendrimers (PADs, also referred to PAMAM)) bind surface QDs by replacing native (oleic acids) ZnO ETL. PAD control rate from ETL into altering electronic energy levels thereby improve...
Quantum dot (QD)-based displays call for nondestructive, high-throughput, and high-resolution patterning techniques with micrometer precision. In particular, self-emissive QD-based demand fine patterns of conductive QD films uniform thickness at the nanometer scale. To meet these requirements, we functionalized QDs photopatternable semiconducting poly(vinyltriphenylamine-random-azidostyrene) (PTPA-N3-SH) ligands in which hole-transporting triphenylamine UV-crosslinkable azide (−N3) groups...
Abstract Endowing quantum dots (QDs) with robustness and durability have been one of the most important issues in this field, since major limitations QDs practical applications are their thermal oxidative instabilities. In work, we propose a facile effective passivation method to enhance photochemical stability using polymeric double shell structures from thiol-terminated poly(methyl methacrylate- b -glycidyl methacrylate) (P(MMA- -GMA)-SH) block copolymer ligands. To generate densely...
Abstract The morphology of heterostructured semiconductor nanocrystals ( h ‐NCs) dictates the spatial distribution charge carriers and their recombination dynamics and/or transport, which are main performance indicators photonic applications utilizing ‐NCs. inability to control heterovalent III‐V/II‐VI ‐NCs composed heavy‐metal‐free elements hinders practical use. As a case study ‐NCs, growth ZnSe epilayers on InP NCs is demonstrated here. anisotropic in InP/ZnSe attributed facet‐dependent...
Quantum dots (QDs) have garnered a significant amount of attention as promising memristive materials owing to their size-dependent tunable bandgap, structural stability, and high level applicability for neuromorphic computing. Despite these advantageous properties, the development QD-based memristors has been hindered by challenges in understanding adjusting resistive switching (RS) behavior QDs. Herein, we propose three types InP/ZnSe/ZnS elucidate RS mechanism, employing thin poly(methyl...
The charge injection imbalance into the quantum dot (QD) emissive layer of QD-based light-emitting diodes (QD-LEDs) is an unresolved issue that detrimental to efficiency and operation stability devices. Herein, integrated approach harmonize rates for bright stable QD-LEDs proposed. Specifically, electronic characteristics hole transport (HTL) delicately designed in order facilitate from HTL QDs confine electron overflow toward HTL. well-defined exciton recombination zone by engineered...
Gallium pnictides, such as GaAs and GaP, are among the most widely used semiconductors for electronic, optoelectronic, photonic applications. However, solution syntheses of gallium pnictide nanomaterials less developed than those many other colloidal semiconductors, including indium II-VI IV-VI compounds, lead halide perovskites. In this work, we demonstrate that Wells dehalosilylation reaction can be carried out in molten inorganic salt solvents to synthesize GaAs, GaP1-xAsx nanocrystals....
The influence of the morphology quantum dot (QD)‐semiconducting polymer hybrid emission layers on performance dot‐based light emitting diodes (QLEDs) is systematically investigated. Chemically grafted QD‐semiconducting hybrids are fabricated by ligand exchange procedure between CdSe/Cd x Zn 1− S QDs and a new block copolymer consisting carbazole‐based electroactive with low highest occupied molecular orbital level disulfide‐based anchor block. QLEDs compared utilizing QD‐only physically...
The state-of-the-art quantum dot (QD) based light-emitting diodes (QD-LEDs) reach near-unity internal efficiency thanks to organic materials used for efficient hole transportation within the devices. However, toward high-current-density LEDs, such as augmented reality, virtual and head-up display, thermal vulnerability of components often results in device instability or breakdown. adoption a thermally robust inorganic transport layer (HTL), NiO, becomes promising alternative, but large...
Reviewed in this paper is the recent progress on interfacial engineering of core/shell heterostructured nanocrystal quantum dots (NQDs) for light-emitting applications, with focus composition (energy) gradient interfaces between core and shell. The engineered mitigate structural stress shell thus reduce chance to create misfit defects that act as efficient non-radiative recombination centers. In addition, resultant smoothening potential profiles across leads strong suppression Auger...
We present ligand-asymmetric Janus quantum dots (QDs) to improve the device performance of dot light-emitting diodes (QLEDs). Specifically, we devise blue QLEDs incorporating QDs with asymmetrically modified ligands, in which bottom ligand contact ZnO electron-transport layer serves as a robust adhesive and an effective electron-blocking top ensures uniform deposition organic hole transport layers enhanced injection properties. Suppressed electron overflow by stimulated enabled contribute...
Due to the strong confinement of carriers, electronic interactions play a major role in performance colloidal nanocrystals (NCs) as materials for optical gain. Therefore, understanding how manipulate this phenomenon is essential achieve feasible devices future. In context, plane quantum wells (PQWs) have emerged one most promising classes NCs be applied lasing material, mainly due way that carriers and light interact these structures. Here, new NC geometry introduced, called spherical well...
Quasi-type II heterostructured nanocrystals (NCs) have been of particular interest due to their great potential for controlling the interplay charge carriers. However, lack material choices quasi-type NCs restricts accessible emission wavelength from red near-infrared (NIR), which hinders use in light-emitting applications that demand a wide range visible colors. Herein, we demonstrate new class nanoemitters formulated ZnSe/ZnSe 1- X Te /ZnSe seed/spherical quantum well/shell...
Abstract Balanced charge injection into the emissive layer is a prerequisite for achieving highly efficient quantum dot light‐emitting diodes (QLEDs). The similar energy distribution of transport layers and indium phosphide (InP) dots (QDs) facilitates excess electron to InP QD layer. In this study, magnesium‐doped ZnO nanoparticles (ZMO NPs) are modified suppress Particularly, hydroxyl groups effectively replaced by electrically stable states through passivation ZMO NPs, retarding NP...
Colloidal quantum dots, with their size-tunable optoelectronic properties and scalable synthesis, enable applications in which inexpensive high-performance semiconductors are needed. Synthesis science breakthroughs have been key to the realization of dot technologies, but important group III–group V semiconductors, including colloidal gallium arsenide (GaAs), still cannot be synthesized existing approaches. The high-temperature molten salt synthesis introduced this work enables preparation...