Superbly Efficient and Stable Ultrapure Blue Phosphorescent Organic Light-Emitting Diodes with Tetradentate Pt(II) Complex with Vibration Suppression Effect.

Blue phosphorescent organic light-emitting diodes (PHOLEDs) are on the brink of commercialization for decades. However, the external quantum efficiency (EQE) and operational lifetime of PHOLEDs are not yet reached industrial standards. Here, a novel tetradentate Pt(II) emitter with a spirofluorene onto the carbazole unit that minimizes the vibration modes, corresponding to the structural relaxation during the de-excitation, called the vibration suppression effect is reported.

Unraveling the Degradation Pathways in Deep Blue Phosphorescent OLEDs Depending on Charge Dynamics: Insights from Numerical Analysis and Magneto-Electroluminescence Characterization.

To analyze the lifetime difference based on the charge dynamics in the emitting layer (EML), we applied two electron transport layers (ETLs) with significantly different electron transporting characteristics to the same EML. Even with the same EML configuration, the device lifetime increased by approximately 4-fold, from 291 h to over 1000 h of LT50 (the time taken for the luminance to decrease to 50% of its initial value of 1000 cd/m). Although trap/detrap of holes in the dopant molecules was observed through impedance spectroscopy, we found that the most significant difference in lifetime was caused by the quantity of electron current.

SERS detection of surface-adsorbent toxic substances of microplastics based on gold nanoparticles and surface acoustic waves.

Microplastics adsorb toxic substances and act as a transport medium. When microplastics adsorbed with toxic substances accumulate in the body, the microplastics and the adsorbed toxic substances can cause serious diseases, such as cancer. This work aimed to develop a surface-enhanced Raman spectroscopy (SERS) detection method for surface-adsorbent toxic substances by forming gold nanogaps on microplastics using surface acoustic waves (SAWs).

Hybridized Local and Charge-Transfer Excited-State Emitter for a Blue Organic Solid-State Laser.

The use of triplet excitons harvesting and short exciton lifetime organic emitters is important to improve the exciton utilization in organic semiconductor laser diodes. In this study, a hybridized local and charge-transfer (HLCT)-type molecule, 11-(3-(10-(4-(1-phenyl-1-phenanthro[9,10-]imidazol-2-yl)phenyl)anthracen-9-yl)phenyl)-11-benzofuro[3,2-]carbazole (PhAnMBf), is used as an emitter for blue-emitting organic solid-state lasers (OSSLs). The short exciton lifetime and high photoluminescence quantum yield of the PhAnMBf emitter allowed the fabrication of an organic laser with an emission wavelength of 453 nm, a small full width at half-maximum of 1.

High Efficiency over 15% by Breaking the Theoretical Efficiency Limit of Fluorescent Organic Light-Emitting Diodes with Localized Surface Plasmon Resonance Effects.

The theoretical efficiency limit of fluorescence organic light-emitting diodes (OLEDs) was successfully surpassed by utilizing the localized surface plasmon resonance (LSPR) effect with conventional emissive materials. The interaction between polaritons and plexcitons generated during the LSPR process was also analyzed experimentally. As a result, the external quantum efficiency (EQE) increased dramatically from 6.

Comparison of Wear of Interim Crowns in Accordance with the Build Angle of Digital Light Processing 3D Printing: A Preliminary In Vivo Study.

The aim of this study is to evaluate the wear volume of interim crowns fabricated using digital light processing 3D printing according to the printing angle. A total of five patients undergoing the placement of a single crown on the mandibular molar were included. Interim crowns were fabricated directly in the oral cavity using the conventional method.

9-(10-phenylanthracen-9-yl)-Benzo[b]Fluoreno[3,4-d] Thiophene Derivatives for Blue Organic Light-Emitting Diodes.

In this study, two blue fluorescence materials using phenylanthracene-substituted fluorene derivatives were synthesized and characterized for organic light-emitting diodes (OLEDs). To study their electroluminescent properties, OLED devices were fabricated using these two materials as emissive layer (EML). A device using 7,7-diphenyl-9-(10-phenylanthracen-9-yl)-7H-benzo[b]fluoreno[3,4-d]thiophene in emitting layer showed the highest value of EQE value which is 3.

Highly Efficient 7,7-Dimethyl-9-(10-phenylanthracen-9-yl)-7H-Benzo[6,7]Indeno[1,2-f]Quinoline Derivatives for Blue Fluorescent Organic Light-Emitting Diodes.

Highly efficient blue fluorescent 7,7-dimethyl-9-(10-phenylanthracen-9-yl)-7H-benzo[6,7]indeno[1,2- f]quinoline derivatives, based on benzo-indeno-quinoline and phenylanthracene were designed and synthesized. To test their electroluminescent properties, organic light-emitting diodes (OLEDs) were fabricated with the configuration of indium-tin-oxide (ITO) (150 nm)/4,4',4″-Tris[2- naphthyl(phenyl)amino]triphenylamine (2-TNATA) (30 nm)/N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'- biphenyl)4,4'-diamine (NPB) (20 nm)/blue emitting materials (20 nm)/bathophenanthroline (Bphen) (30 nm)/Liq (2 nm)/Al (100 nm). The devices using these blue materials as emitters showed efficient blue emission.

7,7-Dimethyl-9-(10-phenylanthracen-9-yl)-7H-Benzo[b] Fluoreno[3,4-d]Thiophene Derivatives for Blue Fluorescent Organic Light-Emitting Diodes.

In this study, we designed and synthesized two blue fluorescence materials using 7,7-dimethyl-9-(10-phenylanthracen-9-yl)-7H-benzo[b]fluoreno[3,4-d]thiophene substituted anthracene derivatives. To characterize their electroluminescent properties, we fabricated the OLED devices using these two emitting materials. Particularly, a device using 7,7-dimethyl-9-(10-phenylanthracen-9-yl)-7Hbenzo[ b]fluoreno[3,4-d]thiophene showed maximum values of luminous efficiency, power efficiency, and external quantum efficiency of 2.

Lightweight user authentication scheme for roaming service in GLOMONET with privacy preserving.

With the development of information technology and the Internet, users can conveniently use roaming services without time and space restrictions. This roaming service is initiated by establishing a session key between a home node, which exists in a home network, and a mobile node, which exists in a foreign network. However, in the process of verifying a legitimate user and establishing a session key, various security threats and privacy exposure issues can arise.

A Secure and Lightweight Three-Factor-Based Authentication Scheme for Smart Healthcare Systems.

Internet of Things (IoT) technology has recently been integrated with various healthcare devices to monitor patients' health status and share it with their healthcare practitioners. Since healthcare data often contain personal and sensitive information, healthcare systems must provide a secure user authentication scheme. Recently, Adavoudi-Jolfaei et al.

Platinum (II) Complexes Based on Tetradentate Pyridine-Containing Ligands for Phosphorescent Organic Light-Emitting Diodes.

In this study, we designed and synthesized two phosphorescent emitting materials based on tetradentate pyridine-containing ligands. Their photophysical properties were examined for OLEDs and multilayer devices using these materials were fabricated in the following sequence; ITO (180 nm)/4,4',4″-Tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA) (30 nm)/,'-di(1-naphthyl)-,'-diphenyl-1,1'-biphenyl)4,4'-diamine (NPB) (20 nm)/Tris(4-carbazoyl-9-ylphenyl)amine (TCTA) (10 nm)/4,4'-Bis(-carbazolyl)-1,1'-biphenyl(CBP): 5, 8, 15% Platinum (II) complexes (20 nm)/1,3,5-Tris(1-Phenyl-1-benzimidazol-2-yl)benzene) (TPBi) (40 nm)/Liq (2 nm)/Al (100 nm). In particularly, a device using Platinum (II) complex based on A/-(3,5-di-tert-butylphenyl)-6-phenyl--(6-phenylpyridin-2-yl)pyridin-2-amine ligand showed the efficient emission, with luminous efficiency, power efficiency, and external quantum efficiency, and the Commission International de LEclairge (CIE) coordinates of 29.

Deep Blue Organic Light-Emitting Diodes Based on [7,7-Dimethyl-9-(10-phenylanthracen-9-yl)-7H-Indeno[1,2-f] Isoquinoline] Derivatives.

In this study, we synthesized and characterized two novel deep blue emitting materials based on indenoquinoline-substituted phenylanthracene derivatives. Multilayer organic light-emitting diodes were fabricated with the following sequence: indium-tin-oxide (ITO)/4,4',4″-tris[2-naphthyl(phenyl)amino (2-TNATA)/4,4'-bis(--naphthyl)--phenylamino) biphenyl (NPB)/Blue emitting material ( or )/Bathophenanthroline (Bphen)/lithium quinolate (Liq)/Al. A device using '7,7-dimethyl-9-(10-phenylanthracen-9-yl)-7H-indeno[1,2-f] isoquinoline ()' as an emitter showed the efficient emission with the luminous efficiency, power efficiency, and external quantum efficiency of 2.

Facile and Novel Eco-Friendly Poly(Vinyl Alcohol) Nanofilters Using the Photocatalytic Property of Titanium Dioxide.

This study aimed to develop a highly efficient nanofilter for capturing fine particles using electrostatic forces. Poly(vinyl alcohol) (PVA), a water-soluble synthetic polymer, was selected as the main component of the filter because it can be easily fabricated by electrospinning. Titanium dioxide (TiO) nanopowder with an anatase structure was applied to the nanofilters as it has the highest photocatalytic activity among the existing photocatalysts.

Blue Fluorescent Organic Light-Emitting Diodes Using 11,11-Dimethyl-3-(10-phenylanthracen-9-yl)-11-Indeno[1,2-]Quinoline Derivatives.

In this study, we designed and synthesized two blue fluorescence materials using phenylanthracenesubstituted-indenoquinoline derivatives by Suzuki coupling reaction for organic light-emitting diodes (OLEDs). In order to study their electroluminescent properties, we fabricated the OLED devices using these two materials as emissive layer (EML) with the following sequence: indium-tin-oxide (ITO, 180 nm)/4,4',4″-tris[2-naphthyl(phenyl)-amino]triphenylamine (2-TNATA, 30 nm)/'-diphenyl-'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB, 20 nm)/Blue emitting materials (20 nm)/4,7-Diphenyl-1,10-phenanthroline (Bphen, 30 nm)/lithium quinolate (Liq, 2 nm)/Al (100 nm). In particular, a device using 11,11-dimethyl-3-(10-phenylanthracen-9-yl)-11-Indeno[1,2-]quinoline in emitting layer showed luminous efficiency, power efficiency, and external quantum efficiency of 2.

Secure and Efficient Three-Factor Protocol for Wireless Sensor Networks.

Wireless sensor networks are widely used in many applications such as environmental monitoring, health care, smart grid and surveillance. Many security protocols have been proposed and intensively studied due to the inherent nature of wireless networks. In particular, Wu et al.

An improved anonymous authentication scheme for roaming in ubiquitous networks.

With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people's lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost.

High-speed time-resolved laser-scanning microscopy using the line-to-pixel referencing method.

Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to visualize photophysical characteristics of biological targets. However, conventional FLIM methods have some limitations that restrict obtaining high-precision images in real time. Here, we propose a high-speed time-resolved laser-scanning microscopy by incorporating a novel line-to-pixel referencing method into the previously suggested analog mean-delay (AMD) method.

Note: Development of a compact aperture-type XYθz positioning stage.

In this paper, we propose a new in-plane XYθz nano-positioning stage that utilizes piezoelectric actuators and flexure mechanisms. The proposed stage has an aperture and is compact, which facilitates its application in measurement equipment, especially those used for biological specimens. The stage has four piezoelectric actuators and four bridge-type flexure mechanisms, which are used to amplify the small motions produced by the piezoelectric actuators.

Optimal design and experiment of a three-axis out-of-plane nano positioning stage using a new compact bridge-type displacement amplifier.

This paper presents the development of a new compact three-axis compliant stage employing piezoelectric actuators and a new flexure structure. A proposed stage works out-of-plane (Z, θx, θy) direction. The stage consists of 4 amplification flexures mounted piezoelectric actuators.