A5069076976- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Semiconductor Quantum Structures and Devices
- Perovskite Materials and Applications
- Nanocluster Synthesis and Applications
- ZnO doping and properties
- Molecular Junctions and Nanostructures
- Semiconductor Lasers and Optical Devices
- Organic Light-Emitting Diodes Research
- Advanced Sensor and Energy Harvesting Materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Tactile and Sensory Interactions
- Nanowire Synthesis and Applications
- Strong Light-Matter Interactions
- Pickering emulsions and particle stabilization
- Photonic Crystals and Applications
- Luminescence and Fluorescent Materials
- Near-Field Optical Microscopy
- Advanced biosensing and bioanalysis techniques
- Luminescence Properties of Advanced Materials
- Porphyrin and Phthalocyanine Chemistry
- 2D Materials and Applications
- Neurobiology and Insect Physiology Research
- Thin-Film Transistor Technologies
- Ga2O3 and related materials
Sungkyunkwan University
2020-2024
Los Alamos National Laboratory
2023-2024
Seoul National University
2017-2019
Quantum dot light-emitting diodes (QLEDs) are one of the most promising candidates for next-generation displays and lighting sources, but they barely used because vulnerability to electrical thermal stresses precludes high brightness, efficiency, stability at current density (J) regimes. Here, bright stable QLEDs on a Si substrate demonstrated, expanding their potential application boundary over present art. First, tailored interface is granted quantum dots, maximizing yield mitigating...
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...
Abstract Colloidal quantum dots (QDs) are attractive materials for realizing solution-processable laser diodes that could benefit from size-controlled emission wavelengths, low optical-gain thresholds and ease of integration with photonic electronic circuits 1–7 . However, the implementation such devices has been hampered by fast Auger recombination gain-active multicarrier states 1,8 , poor stability QD films at high current densities 9,10 difficulty to obtain net optical gain in a complex...
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...
InP quantum dots (QDs) based light-emitting diodes (QLEDs) are considered as one of the most promising candidates a substitute for environmentally toxic Cd-based QLEDs future displays. However, device architecture is almost same even though properties and InP-based QDs quite different in their energy levels shapes. Thus, it highly required to develop proper structure improve efficiency stability. In this work, efficient, bright, stable InP/ZnSeS on an inverted top emission QLED (ITQLED) by...
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...
Electroluminescence from quantum dots (QDs) is a suitable photon source for futuristic displays offering hyper-realistic images with free-form factors. Accordingly, nondestructive and scalable process capable of rendering multicolored QD patterns on scale several micrometers needs to be established. Here, direct photopatterning heavy-metal-free QDs reported using branched light-driven ligand crosslinkers (LiXers) containing multiple azide units. The LiXers effectively interlock films via...
Abstract Wide interest in quantum dot (QD) light‐emitting diodes (QLEDs) for potential application to display devices and light sources has led their rapid advancement device performance. Despite such progress, detailed operation mechanisms of QLEDs, which are necessary the fundamental understanding further improvements, have been still uncertain because intricate interaction between charges excitons electrical operation. In this work, transient electroluminescence (TREL) signals dichromatic...
Heteroepitaxy on colloidal semiconductor nanocrystals is an essential strategy for manipulating their optoelectronic functionalities. However, practical synthesis typically leads to scattered and unexpected outcomes due the intervention of multiple reaction pathways associated with complicated side products reactants. Here, heteroepitaxy mechanism zinc chalcogenide initiated indium phosphide (InP) elucidated using precursors, carboxylate trialkylphosphine selenide. The high magnetic...
Quantum dots (QDs) exhibit size-tunable optical properties, making them suitable for efficient light-sensing and light-emitting devices. Tandem devices that can convert near-infrared (NIR) to visible (Vis) signals be fabricated by integrating an NIR-sensing QD device with a Vis electroluminescence (EL) device. However, these require delicate control of the layer during processing prevent damage predeposited layers in tandem subsequent deposition other functional layers. This has restricted...
Present-day liquid-state lasers are based on organic dyes. Here we demonstrate an alternative class of liquid that use solutions colloidal quantum dots (QDs). Previous efforts to realize such devices have been hampered by the fast non-radiative Auger recombination multicarrier states required for optical gain. overcome this challenge using type-(I + II) QDs, which feature a trion-like gain state with strongly suppressed recombination. When combined Littrow cavity, static (non-circulated)...
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...
Incorporating manganese (Mn) impurities into II-VI semiconductors alters their properties through strong exchange interactions with the host material. In colloidal quantum dots (QDs), these enable ultrafast bidirectional energy transfer between magnetic impurity and QD intrinsic states, rates exceeding rate of loss via phonon emission. This suggests that Mn-QD could harness hot carrier before dissipation. Here, we demonstrate by using Mn-doped CdSe/HgSe core/shell QDs, can efficiently...
The rising demand for eradicating hazardous substances in the workplace has motivated vigorous researches on environmentally sustainable manufacturing processes of colloidal quantum dots (QDs) their optoelectronic applications. Despite remarkable achievements witnessed QD materials (e.g., Pb- or Cd-free QDs), progress eco-friendly process is far falling behind and thus practical use QDs. Herein, a complete "green" QDs, which excludes unfriendly elements from ligands, solvents, presented....
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...
Active matrix (AM) quantum-dot light-emitting diodes (QLEDs) driven by thin-film transistors (TFTs) have attracted significant attention for use in next-generation displays. Several challenges remain the realisation of AM-QLEDs, such as device design, fabrication process, and integration between QLEDs TFTs, depending on their structures configurations. Herein, efficient stable AM-QLEDs are demonstrated using conventional inverted structured (C- I-QLEDs, respectively) combined with facile...
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...
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...
Electronic skin (E-skin) based on tactile sensors has great significance in next-generation electronics such as biomedical application and artificial intelligence that requires interaction with humans. To mimic the properties of human skin, high flexibility, excellent sensing capability, sufficient spatial resolution through high-level sensor integration are required. Here, we report a highly sensitive pressure matrix piezoresistive cellulose/single-walled carbon nanotube-entangled fiber...