Metal oxide charge transfer complex for effective energy band tailoring in multilayer optoelectronics.

Metal oxides are intensively used for multilayered optoelectronic devices such as organic light-emitting diodes (OLEDs). Many approaches have been explored to improve device performance by engineering electrical properties. However, conventional methods cannot enable both energy level manipulation and conductivity enhancement for achieving optimum energy band configurations.

Extremely Stable Luminescent Crosslinked Perovskite Nanoparticles under Harsh Environments over 1.5 Years.

Organic-inorganic hybrid perovskite nanoparticles (NPs) are a very strong candidate emitter that can meet the high luminescence efficiency and high color standard of Rec.2020. However, the instability of perovskite NPs is the most critical unsolved problem that limits their practical application.

Highly Efficient Deep Blue Cd-Free Quantum Dot Light-Emitting Diodes by a p-Type Doped Emissive Layer.

Environmentally friendly ZnSe/ZnS core/shell quantum dots (QDs) as an alternative blue emission material to Cd-based QDs have shown great potential for use in next-generation displays. However, it remains still challenging to realize a high-efficiency quantum dot light-emitting diode (QLED) based on ZnSe/ZnS QDs due to their insufficient electrical characteristics, such as excessively high electron mobility (compared to the hole mobility) and the deep-lying valence band. In this work, the effects of QDs doped with hole transport materials (hybrid QDs) on the electrical characteristics of a QLED are investigated.

Thermodynamic-driven polychromatic quantum dot patterning for light-emitting diodes beyond eye-limiting resolution.

The next-generation wearable near-eye displays inevitably require extremely high pixel density due to significant decrease in the viewing distance. For such denser and smaller pixel arrays, the emissive material must exhibit wider colour gamut so that each of the vast pixels maintains the colour accuracy. Electroluminescent quantum dot light-emitting diodes are promising candidates for such application owing to their highly saturated colour gamuts and other excellent optoelectronic properties.

Enhancing the luminescence of carbon nanodots in films by tailoring the functional groups through alkylamine-functionalization and reduction.

Enhancing the luminescence efficiency and stability of solid-state phosphors with facile processability is important for various applications. Carbon-based materials might have proper optical features and durability under ambient conditions. However, carbon-based phosphors usually showed severe quenching of the photoluminescence in the absence of solvent.

Order-of-Magnitude, Broadband-Enhanced Light Emission from Quantum Dots Assembled in Multiscale Phase-Separated Block Copolymers.

Achieving high emission efficiency in solid-state quantum dots (QDs) is an essential requirement for high-performance QD optoelectronics. However, most QD films suffer from insufficient excitation and light extraction efficiencies, along with nonradiative energy transfer between closely adjacent QDs. Herein, we suggest a highly effective strategy to enhance the photoluminescence (PL) of QD composite films through an assembly of QDs and poly(styrene--4-vinylpyridine)) (PS--P4VP) block copolymer (BCP).

A feasible strategy to prepare quantum dot-incorporated carbon nanofibers as free-standing platforms.

Recently, quantum dots (QDs) have often garnered significant attention and have been employed for various applications. Nevertheless, most conventional devices utilize a glass substrate and/or brittle substrate, which is not compatible with next-generation wearable electronics. A suitable method for devising conductive and flexible free-standing platforms that can be combined with various kinds of QDs is thus in great need for next-generation wearable electronics.

Mixture of quantum dots and ZnS nanoparticles as emissive layer for improved quantum dots light emitting diodes.

Recently, quantum dots based light-emitting diodes (QLEDs) have received huge attention due to the properties of quantum dots (QDs), such as high photoluminescence quantum yield (PLQY) and narrow emission. To improve the performance of QLEDs, reducing non-radiative energy transfer is critical. So far, most conventional methods required additional chemical treatment like giant shell and/or ligands exchange.

Correlation of near-unity quantum yields with photogenerated excitons in X-type ligand passivated CsPbBr perovskite quantum dots.

We investigated the exciton decay dynamics of CsPbBr perovskite quantum dots (PQDs) through an X-type ligand passivation process. 1-Dodecanethiol (DDT), as an X-type ligand, covers Br vacancies of PQDs and then the photoluminescence quantum yield (PLQY) sharply improved from 76.1% to 99.

A highly luminescent quantum dot/mesoporous TiO nanocomplex film under controlled energy transfer.

We have prepared a highly luminescent quantum dot (QDs)-TiO2 nanocomplex film by the dip coating method. Because QDs with 3-mercaptopropionic acid as a ligand adsorb ionized Ti+ cations on the TiO2 particle, the average distance between the QDs can be changed through controlling the porosity in the film. The porosity is controlled using ethyl cellulose (EC).

Spontaneous Registration of Sub-10 nm Features Based on Subzero Celsius Spin-Casting of Self-Assembling Building Blocks Directed by Chemically Encoded Surfaces.

For low-cost and facile fabrication of innovative nanoscale devices with outstanding functionality and performance, it is critical to develop more practical patterning solutions that are applicable to a wide range of materials and feature sizes while minimizing detrimental effects by processing conditions. In this study, we report that area-selective sub-10 nm pattern formation can be realized by temperature-controlled spin-casting of block copolymers (BCPs) combined with submicron-scale-patterned chemical surfaces. Compared to conventional room-temperature spin-casting, the low temperature ( e.

Controlled Synthesis of CuInS/ZnS Nanocubes and Their Sensitive Photoluminescence Response toward Hydrogen Peroxide.

We synthesized uniform CuInS/ZnS nanocubes by adjusting reaction parameters at the ZnS growth stage. Higher temperature and zinc concentration were shown to drive resultant crystals to have cubic morphology, which could be ascribed to the facet-dependent ligand dynamics on the crystal surface and concomitantly preferred directions of crystal growth. It was found that these nanocubes exhibit sensitive responses, as of photoluminescence quenching, toward hydrogen peroxide, compared to pyramid-shaped nanocrystals.

Solution processible MoO-incorporated graphene anode for efficient polymer light-emitting diodes.

Graphene has attracted great attention owing to its superb properties as an anode of organic or polymer light-emitting diodes (OLEDs or PLEDs). However, there are still barriers for graphene to replace existing indium tin oxide (ITO) due to relatively high sheet resistance and work function mismatch. In this study, PLEDs using molybdenum oxide (MoO) nanoparticle-doped graphene are demonstrated on a plastic substrate to have a low sheet resistance and high work function.

High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure.

Imidazolium ionic side-group-containing fluorene-based conjugated polyelectrolytes (CPEs) with different π-conjugated structures, poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (F8im-Br) and poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-(benzo(2,1,3)thiadiazol-4,8-diyl) dibromide (F8imBT-Br), are synthesized and utilized as an electron injection layer (EIL) in green-emitting F8BT polymer light-emitting diodes (PLEDs). Both CPE EIL devices significantly outperform Ca cathode devices; 17.9 cd A(-1) (at 3.

Electrostatic Stabilized InP Colloidal Quantum Dots with High Photoluminescence Efficiency.

Electrostatically stabilized InP quantum dots (QDs) showing a high luminescence yield of 16% without any long alkyl chain coordinating ligands on their surface are demonstrated. This is achieved by UV-etching the QDs in the presence of fluoric and sulfuric acids. Fluoric acid plays a critical role in selectively etching nonradiative sites during the ligand-exchange process and in relieving the acidity of the solution to prevent destruction of the QDs.

Enhancing the light utilization efficiency of microalgae using organic dyes.

Solar radiation is composed of wide light spectrum including the range which cannot be utilized for microalgae. To enhance the light utilization efficiency, organic dye solutions of rhodamine101 and 9,10-diphenylanthracene were used as wavelength converters. Each dye affected cell growth and lipid accumulation differently, based on the response of each to different light spectrum.

Serum-stable quantum dot-protein hybrid nanocapsules for optical bio-imaging.

We introduce shell cross-linked protein/quantum dot (QD) hybrid nanocapsules as a serum-stable systemic delivery nanocarrier for tumor-targeted in vivo bio-imaging applications. Highly luminescent, heavy-metal-free Cu0.3InS2/ZnS (CIS/ZnS) core-shell QDs are synthesized and mixed with amine-reactive six-armed poly(ethylene glycol) (PEG) in dichloromethane.

Energy transfer in Sr2MgSi2O7:Eu2+ phosphors in nano scale and their application to solid state lighting with excellent color rendering.

On the basis of structural information of its host material which shows excellent stability and absorption efficiency in ultra-violet (UV) region, a blue-emitting Sr2MgSi2O7:Eu2+ (SMS:Eu2+) phosphor was synthesized, and its photoluminescence (PL) performance was systematically optimized. In order to enhance its PL properties, Ce3+ was added as a sensitizer based on the energy transfer from the absorption energy of Ce3+ to Eu2+. It was due to the spectral overlap between the photoluminescence excitation spectrum of Ce3+ and the PL spectrum of Eu2+.

Tunable emission from blue to white light in single-phase Na(0.34)Ca(0.66-x-y)Al(1.66)Si(2.34)O8:xEu2+,yMn2+ (x = 0.07) phosphor for white-light UV LEDs.

A series of single-phased emission-tunable Na(0.34)Ca(0.66)Al(1.

Exciton dissociation and charge-transport enhancement in organic solar cells with quantum-dot/N-doped CNT hybrid nanomaterials.

The incorporation of InP quantum-dot/N-doped multiwalled carbon nanotube (QD:NCNT) nanohybrids in the active layer of poly(3-hexylthiophene)/indene-C60 bisadduct (P3HT/ICBA) bulk-heterojuction solar cells enhances V(OC) and J(SC) . The QDs encourage exciton dissociation by promoting electron transfer, while the NCNTs enhance the transport of the separated electrons and eventual charge collection. Such a synergistic effect successfully improves the power conversion efficiency (PCE) from 4.

Novel blue-emitting Na(x)Ca(1-x)Al(2-x)Si(2+x)O8:Eu2+ (x = 0.34) phosphor with high luminescent efficiency for UV-pumped light-emitting diodes.

A novel blue-emitting phosphor, Na(0.34)Ca(0.66)Al(1.

Bendable inorganic thin-film battery for fully flexible electronic systems.

High-performance flexible power sources have gained attention, as they enable the realization of next-generation bendable, implantable, and wearable electronic systems. Although the rechargeable lithium-ion battery (LIB) has been regarded as a strong candidate for a high-performance flexible energy source, compliant electrodes for bendable LIBs are restricted to only a few materials, and their performance has not been sufficient for them to be applied to flexible consumer electronics including rollable displays. In this paper, we present a flexible thin-film LIB developed using the universal transfer approach, which enables the realization of diverse flexible LIBs regardless of electrode chemistry.

Synthesis of green emitting and transparent zn2siO4:mn2+ thin film phosphors on 2D photonic crystal patterned quartz substrates.

Zn2SiO4:Mn2+ thin film phosphors (TFPs) have been synthesized by RF magnetron sputtering, using a single multicomponent stoichiometric target. And 2D photonic crystal patterns were introduced on a quartz substrate to enhance the light extraction efficiency. In order to introduce 2D photonic crystal patterns on a quartz substrate, nanosphere lithography was used.

Photoluminescence enhancement of synthesized ZnS-based-nanocrystals and aging effect on its emitting color.

Various colors-emitting ZnS:Cu,Cl, ZnS:Cu,Cl,Mn and ZnS:Mn nanocrystals (NCs) which were shown to be about 3 nm sized-particle were synthesized by using a solution chemistry. And the luminescences of the synthesized ZnS-based NCs were investigated through photoluminescence excitation (PLE) and photoluminescence (PL) spectroscopy. The PLE and PL intensities of the ZnS-based NCs depends on their reflux time, and red shifted maximum PLE wavelengths of the synthesized NCs showed with increasing reflux time.