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Four bipolar molecules, named 1-, 2-, 3-, and 4-3cbzBIZ, composed of tricarbazole (3cbz) substituted benzimidazole, were synthesized and characterized.

This work highlights the importance of bis(triarylamine) redox-active linker in promoting the semiconductive and photoconductive behavior of a 2D zinc-based coordination polymer.

With the combination of a benzimidazole-carbazole backbone and AIE luminophores, highly sensitive and selective turn-on fluorescent probes are achieved and applicable for differential detection of strong acids in weak acids.

In this study, we develop a steady state and time-dependent exciton diffusion model including singlet and triplet excitons coupled with a modified Poisson and drift-diffusion solver to explain the mechanism of hyper triplet-triplet fusion (TTF) organic light-emitting diodes (OLEDs). Using this modified simulator, we demonstrate various characteristics of OLEDs, including the J-V curve, internal quantum efficiency, transient spectrum, and electric profile. This solver can also be used to explain the mechanism of hyper-TTF-OLEDs and analyze the loss from different exciton mechanisms. Furthermore, we perform additional optimization of hyper-TTF-OLEDs that increases the internal quantum efficiency by approximately 33% (from 29% to 40%).

BackgroundAdult antibody deficiency remains under-recognised and under-studied – especially among Asian populations. Patterns of immunoglobulin use and the feasibility of subcutaneous immunoglobulin (SCIg) replacement among Chinese patients remains unclear.ObjectiveTo investigate the trends of immunoglobulin use, burden of adult antibody deficiency and the outcomes of patients on SCIg compared to intravenous immunoglobulin (IVIg) replacement in Hong Kong through a retrospective observational study.MethodsPopulation-wide data of immunoglobulin recipients in Hong Kong between 2012 and 2021, and longitudinal clinical data of adult immunodeficiency patients at Queen Mary Hospital were collected and analysed.ResultsTotal immunoglobulin consumption and recurrent immunoglobulin recipients increased continuously from 175,512g to 298,514g (ρ=0.99, pConclusionThere was a significantly increasing burden of adult antibody deficiency and immunoglobulin consumption in Hong Kong. SCIg was feasible and more cost-effective when compared to IVIg, with SCIg patients experiencing better clinical outcomes and quality of life. Future prospective studies to confirm the long-term efficacy and superiority of SCIg are required.

This work describes the synthesis and characterization of a Zn-based metal-organic framework, [Zn2(TTPA)(SDB)2·(DMF)(H2O)]n (1, TTPA = tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine, SDB = 4,4'-sulfonyldibenzoate). A newly designed strategy with a redox-active linker, TTPA, and mediated by a V-shaped carboxylic linker with Zn2+ metal ions resulted in an electroactive framework. The V-shaped carboxylic linker with Zn2+ metal ions forms linear struts interlinked by two of the side-arms of the TTPA ligands to form a square grid network. The interior of the grid is enough to accommodate the third side-arm of the TTPA ligands, acting as a confinement grid that provides steric protection when triarylamine radical cations were generated. In addition, modular packing of axially aligned TTPA ligand facilitates charge propagation. Optical switching studies confirmed that 1 is electrochemically reversible up to 48 cycles at a potential of 0.9 V vs Fc/Fc+. Framework 1 remained robust after annealing at 180 °C for 20 h as corroborated by the PXRD. These studies confirm the importance of crystal engineering design, where electron transfer is possible in a two-ligand approach.

35Cbz4BzCN, a novel universal host with a long triplet lifetime, has been developed. The triplet excitons in 35Cbz4BzCN can be effectively harvested by phosphorescence and thermally activated delayed fluorescence emitters. In the 4CzIPN doped device, the best performance of a maximum current efficiency of 111.8 cd A−1, power efficiency of 86.8 lm W−1, and external quantum efficiency of 31.7% with a small efficiency roll-off of 103 cd A−1 at 1000 cd m−2 has been achieved. 35Cbz4BzCN is also compatible with FIrpic to give sky-blue emission up to 46.3 cd A−1 and with TXO-TPA to give orange-red emission up to 60.6 cd A−1 efficiency.

An efficient one-pot synthesis of oxazolidinones was developed through CuI/DBU/MS joint system-catalyzed carboxylative cyclization of arylacetylene, arylaldehyde, and arylamine in water medium under a 1 atm carbon dioxide (CO2) atmosphere. The 4 A molecular sieves (MSs) were added to improve CO2 capture and facilitate carboxylation to give the products in high yields. The CuI/DBU/MS system is robust and highly effective for the reactions with different substrates, and some target products were obtained in an excellent yield of ∼96%, with no side products in the final step.

Two bipolar hosts, 8-cbzBIFP and 10-cbzBIFP, both with basic skeletons of orthogonally-connected carbazole and benzimidazo〈1,2-f〉phenanthridine (BIFP) have been prepared. The planar structure of the BIFP moiety governs the molecular stacking in the crystal lattice. Electron transport properties, in comparison to the benzimidazole derivatives, are facilitated. Both hosts display fabulous performances in phosphorescent organic light-emitting diodes with bis(2-phenylpyridine)(acetylacetonate)iridium(III) as an emitter. The optimized green PhOLED of 10-cbzBIFP achieves the maximum brightness (Lmax) of 58 810 cd m−2, the maximum current efficiency (ηc) of 87.0 cd A−1 and external quantum efficiency (EQE) of 21.1%. Likewise, 8-cbzBIFP shows an Lmax of 58 870 cd m−2, ηc of 77.3 cd A−1 and EQE of 19.1%.

Triplet is like a double-edged knife, that can degrade or benefit the electroluminescence performances of organic light-emitting diodes (OLEDs), especially for blue light. Therefore, efficient triplet harvesting for triplet-triplet fusion (TTF) fluorescence emission is essential to achieving high-efficiency blue TTF-OLEDs, which are known for their excellent reliability. This study presents a hyper-TTF mechanism for maximizing triplet exciton usage and avoiding triplet-polaron quenching to generate more photons through Dexter energy transfer (DET) and TTF processes. Specially, a triplet tank layer (TTL) was introduced adjacent to the TTF emitting layer (EML). Efficient carrier recombination and triplet generation are confined to the TTL of the device. Most triplets were observed to undergo DET from the TTL to the TTF EML; they subsequently became singlets exhibiting delayed fluorescence. Furthermore, the triplet-polaron quenching is suppressed by inhibiting hole into the TTF EML. A record-high TTF-OLED efficiency was achieved with an external quantum efficiency of 15.4%.

The recent progress of efficiency improvement, emission color tuning, and lifetime elongation of blue organic light-emitting diodes (OLEDs) is reviewed. The latter is one of the most important bottlenecks for OLED development. The current status of blue light-emitting material design with emission mechanisms such as fluorescence (F), phosphorescence (Ph), thermally activated delayed fluorescence (TADF), and hybridized local and charge transfer (HLCT) is introduced in the first part of this review. Compared to red and green devices, the long exciton lifetime of the high energy triplet exciton in a blue OLED is the one of the main issues. To avoid the accumulation of high energy triplet excitons in the emitter for blue OLEDs, assisted triplet–triplet fluorescence (TTF) and Hyperfluorescence™ are employed to harvest the triplet excitons. In the second part of this review, we focus on issues from an application viewpoint: what are the requirements of blue OLEDs for display and lighting technologies in terms of efficiency, color, and lifetime? Key performance metrics of blue OLEDs with different technologies over time are summarized. Independent of technology, the trend is similar: the external quantum efficiency improves for the first stage of research, followed by color tuning, and then finally lifetime elongation. The state-of-the-art device performance of blue OLEDs with various emission mechanisms is illustrated. Although Ph- and TADF-emission based devices show satisfactory efficiency and electroluminescence (EL) spectra, despite having a lower efficiency TTF-emission based devices are the mainstream for real applications due to their relatively long operation lifetime. Blue Ph-OLEDs have the potential for lighting applications with suitable material selection and device design. We collected the published results and tried our best to make a fair comparison of the operation lifetime among different technologies. Finally, we discuss the possible future outlook from different viewpoints including new materials, device designs, and applications of blue OLEDs.

Recently, a new emission mode, triplet-triplet annihilation up conversion (TTAUC), of OLED was proposed with the mechanism as follows: when the carriers recombine at the sensitizer layer with a lower energy bandgap, the generated triplet excitons of sensitizer transfer to the triplet-triplet annihilation (TTA) emitter and emit a higher energy photon. In our experiment, we used tris(8-hydroxyquinolinato)aluminum (Alq3) as sensitizer, 9,10-Bis(2-naphthyl)anthraces (ADN) as TTA emitter and 1,1'-(2,5-Dimethyl-1,4-phenylene)dipyrene (DMPPP) as triplet diffusion singlet blocking (TDSB) layer. To improve the efficiency of TTAUC-OLED, 4,4’ -Bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), was doped in ADN host. With 6% of DPAVBi doping, no obvious change was observed in electrical characteristics, indicating electron traps from dopant is limited. Maximum EQE achieved EQE= 4.66% in the optimized device.

In this study, we report a bistriazoles derivative to be the wide bandgap host for blue emitters. In particular, this bistriazoles derivative possesses a wide bandgap of 4.0 eV and bipolar carrier transportation behavior. In addition, its bipolar behavior is classified to the rare case of electron-favorable bipolar carrier transportation, which was identified by the time-of-flight measurement and unipolar device. The electron mobility is little faster than hole one, which benefits the adjustment of carrier balance in the emitting layer. Employing to be the host of blue phosphorescent OLED, the device exhibits a high-efficiency performance with a 30.2%EQE.

A numerical solver based on two-dimensional Poisson and drift-diffusion equations with Gaussian-shaped density of states, the Poole-Frenkel field mobility model, and the Ising model are proposed to analyze carrier transport in the host-guest systems based on organic semiconductors. To investigate the performance of this solver, a series of the electron-only devices and hole-only devices are fabricated with different dopant concentrations. The space-charge-limited current model is applied to the simulation results to calculate the mobility. In addition, experimental results for different host-guest systems are compared to prove the accuracy of the solver. The solver is able to explain the physical mechanisms in different situations. At lower dopant concentrations, the guest states act as traps. Carriers are localized in these guest states, and the carrier mobility decreases dramatically. At the higher dopant concentrations, regions of guest material are able to connect with each other, and carriers have a probability to hop through the guest states. The mobility characteristics gradually approach those of the pure guest material.

An efficient one-pot synthesis of oxazolidinones was developed through CuI/DBU/MS joint system-catalyzed carboxylative cyclization of arylacetylene, arylaldehyde, and arylamine in water medium under a 1 atm carbon dioxide (CO

A emission mode based on triplet-triplet annihilation up conversion (TTAUC) was proposed as follows: when the electrons and holes recombined at the sensitizer layer with a lower energy bandgap, the triplet exciton of sensitizer can transfer the energy to the triplet-triplet annihilation (TTA) emitter and emit a higher energy blue photon. TTAUC-OLEDs had proved to have a higher device efficiency with tris(8-hydroxyquinolinato)aluminum (Alq3) as sensitizer and 9,10-Bis(2-naphthyl)anthraces (ADN) as TTA emitter. In this research, we employed Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2) to replace Alq3 which had a higher electron mobility and resulted in a better electrical properties. It showed a higher current density at constant voltages and the turn-on voltage (at 1 cd/m2) decreased 0.3V compared to Alq3 as sensitizer. Bebq2 as sensitizer achieved a higher efficiency with 3.26% in overall EQE, together with 1.91% and 1.35% in blue and green EQE at J=6.71 mA/cm2 compared to Alq3

This work reports on the facile synthesis, characterization, and electroactivity of a zinc-based [Zn3(TTPA)2(DHTP)3]·2DMF (1, TTPA = tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine, DHTP = dihydroxylterepthate) metal-organic framework, which has multifunctional properties due to its electroactive framework, permanent porosity, robust structure, and fluorescent nature. Topology analyses indicate that 1 contains a 3,4,4-c net. Sorption studies indicate that 1 is a suitable adsorbent for CO2 with a capacity of 10.2 wt % at 298 K; the capacity increased to 16.7 wt % at a lower temperature, 273 K. The incorporation of the redox-active TTPA ligand as an electron donor renders 1 to be an electroactive framework. The generation of radical cations from the chemical oxidation of 1 resulted in fluorescent quenching. The combination of porosity, fluorescence, and electroactivity in one entity suggests that 1 could serve as a sensing material for the detection of nitrobenzene. Exposing nitrobenzene to 1 quenches the fluorescent via host-guest interactions. The detection site of nitrobenzene in framework 1 was confirmed by single-crystal X-ray diffraction, [Zn3(TTPA)2(DHTP)3]·(H2O)(DMF)(2NB) or 1 ⊂ NB. In addition, the inclusion of nitrobenzene into the framework 1 stabilized the disordered molecules via strong hydrogen bonding. These findings indicate that versatile MOFs with multifunctional properties can be realized via a systematic design.

The efficient conversion of electron-hole (e-h) pairs into triplet excitons is a challenge for blue organic light-emitting diodes (OLEDs) based on triplet–triplet annihilation upconversion (TTAUC). The 25% fraction of e-h pairs that create singlet excitons represents a significant loss channel that can lead to parasitic red-shifted emission. In this study, an intermolecular intersystem crossing that relies on a “dark sensitizer” (DS) layer consisting of tris-(8-hydroxyquinoline)aluminum (Alq3) doped with tris[2-phenylpyridinato-C2,N]Iridium(III) (Ir(ppy)3) is demonstrated to enhance the TTAUC process. Carriers recombination and excitons generation are formed on Alq3 molecules. Alq3 singlet excitons are then quenched by the Ir(ppy)3 triplet state, followed by energy transfer to the Alq3 triplet state. The non-emissive, long-lived Alq3 triplets migrate from the sensitizer layer to an emitter layer where they undergo TTAUC to give blue fluorescence emission. This DS-TTAUC process promises no green emission from the Alq3. The efficiency of a blue OLED utilizing DS-TTAUC was improved by 34.2% compared to a standard TTAUC OLED. In addition, the device exhibited CIE coordinates of (0.15, 0.09). Furthermore, a high photoluminescence quantum yield fluorescence emitter is incorporated to enhance the singlet exciton emission in the emitter layer. A maximum external quantum efficiency of 7.54% can be achieved with recorded-high quantum yield of the TTAUC (ΦTTAUC) = 37.6% in solid state.

The inclusion of a tetraphenylbenzene (4Ph) unit in thermally activated delayed fluorescence emitters is demonstrated as a novel strategy for greatly enhancing the horizontally oriented alignment of the emitters without shifting the emission spectrum to longer wavelengths. Doping of blue-emitting 4PhOXDDMAC or greenish-blue-emitting 4PhOXDPXZ into o-DiCbzBz host layers yielded much higher degrees of horizontally oriented alignment for the emitter (up to 92%) compared to those when the 4Ph unit was excluded (69 and 75%, respectively). The enhanced alignment results in high outcoupling efficiencies of 24 and 35% in organic light-emitting diodes based on 4PhOXDDMAC and 4PhOXDPXZ, respectively, and boosts the external quantum efficiencies to values (8.8 and 29.2%, respectively) that are higher than what would be expected for randomly oriented emitters (outcoupling efficiency of 20%). These enhancements are achieved while avoiding the redshift that often occurs using the common strategy of increasing molecular length and, thereby, conjugation, to increase orientation.

A new 3D coordination polymer {[Co2(μ-OH2)(TTPA)(DTDN)2·DMF]·H2O}n (1, TTPA = tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine, DTDN = 6,6'-dithiodinicotinate) was synthesised and characterised. The redox properties of this framework were elucidated by solid state electrochemical and spectroelectrochemical data. This is the first investigation of the redox behaviour of TTPA in coordination polymers. Furthermore, the incorporation of a paramagnetic Co(ii) metal ion into the framework caused 1 to show spin-flop behaviour as the result of a field-induced magnetic transition. The incorporation of two flexible ligands and Co(ii) metal ions represents a feasible approach for the advancement of multifunctional materials.

We have successfully synthesized a series of thermally cross-linkable azide-substituted poly(N-ethyl-3-vinylcarbazoles) P1–P6. These polymers can be self-cross-linked by heat treatment under atmospheric conditions to form insoluble polymer matrices. Their electronic properties can be tuned by using various triphenylamine-substituted alkyne-based curing agents as additives. The polymeric materials can be simply coated on a substrate by spin coating or dip coating. Through the Huisgen 1,3-dipolar cycloaddition reaction, the polymeric film can be cured by alkyne-based curing agents effectively under copper-free conditions. This approach can be utilized in the fabrication of multilayer polymeric light-emitting devices (PLEDs). Under optimized conditions, we have demonstrated that the PLED of ITO/cured P5/PVK-Ir(ppy)3-t-PBD/Mg–Ag shows a turn-on voltage of 10.1 V (1 cd/m2), with the maximum brightness of 7851 cd/m2 and current efficiency of 12.8 cd/A.

An ambipolar compound, 9-(2-(4,5-diphenyl-4 H -1,2,4-triazol-3-yl)phenyl)-9 H -carbazole, is employed as a universal single host for efficient sky-blue (B), green (G), orange–red (R), BG, and white (W) phosphorescent organic light-emitting diodes (PhOLEDs) with an external quantum efficiency (η EQE ) of more than 20%. By integrating B and G emitters into the emitting layer (EML), an efficient BG PhOLED exhibits a maximum current efficiency (η C ) of 81.7 cd/A, power efficiency (η P ) of 73.2 lm/W, and η EQE of 23.1%. Another BG PhOLED exhibits excellent colour stability with a slight shift (Δ x of 0.0006, Δ y of 0.0014) in CIE1931 colour coordinates while its luminance varies from 3.5 to 38360 cd/m 2 . Furthermore, a 1 nm R EML is employed as a probe inserted at three distinct positions to investigate the main recombination zone; the main recombination zone is detected near the interface between B/G EML. At the same time, a W spectrum combines individual R, G, B emission peaks. Besides, a W PhOLED simply comprises of a B and R EML, exhibiting good colour stability (Δ x of 0.0004, Δ y of 0.0023 between 4 and 12 V) and high efficiency (a maximum η C , η P , η EQE of 58.4 cd/A, 50.7 lm/W, 21.9%). In addition, transient electroluminance signals described green emitters have less trapped charges and a longer exciton lifetime which benefit the device lifetime.

1,3,5-(N,N′,N′′)-Tricarbazolyl-2-(benzimidazol-2-yl)benzene (TCbzBz) has been developed as a host for the FIrpic doped blue phosphorescent organic light emitting diodes. The Y-shaped 1,3,5-tricarbazole array networks the host molecules to form continuous hole and electron hopping paths that provide an improved hole mobility of 2.0 × 10−5 cm2 V−1 s−1. Significant breakthroughs on the efficiency of 58.2 cd A−1 and 59.4 lm W−1 with 28% of external quantum efficiency are therefore achieved. Usually aggregation of the emitter molecules will lead to triplet–triplet quenching and significantly hamper the performance of the PhOLEDs. However, the present networked matrix is so spacious that it can accommodate up to 12% of the FIrpic without hampering the device performance. Nano-aggregation in the sublimed film is clearly evidenced by atomic force microscopy, powder X-ray diffractometry, and UV-Vis spectrophotometry.

This work describes the successful incorporation of a redox active linker, tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine (TTPA) into Mn(II)/Cu(II) based coordination frameworks. Solution state in situ spectroelectrochemistry of EPR and UV/Vis/NIR of the TTPA ligand were measured to gain a deeper understanding of the charge delocalization of the triphenylamine backbone. The assignments of the absorption bands for the radical cations in UV/Vis/NIR spectroelectrochemistry were supported by DFT calculations. For Mn(II)/Cu(II) based coordination frameworks, solid state electrochemical and in situ spectroelectrochemical methods were applied to elucidate the accessible redox states and the optical properties of the frameworks. The findings provide a basic comprehension of the interconversion of different redox states and how an electroactive framework can be potentially used in applications of electrochromic and optical devices.

Organic light emitting diode (OLED) has lots of advantages in display technology such as self-emissive, light-weight, and compatible for flexible substrates. Compared to the red and green OLEDs, blue one has shorter lifetime due to high-energy polaron quenching. Triplet-triplet annihilation up conversion (TTAUC) is a promising way to reduce the driving voltage and improve the operation lifetime for a blue OLED. This system includes two materials, sensitizer and emitter, which has a narrower bandgap and triplet-triplet annihilation (TTA) characteristic, respectively. When the sensitizer is excited, its triplet exciton can transfer the energy to the triplet of emitter with lower triplet energy and fuse into one singlet exciton with a higher energy photon than the sensitizer. In this research, we demonstrate that a convention green fluorescent material, tris(8-hydroxyquinolinato)aluminum (Alq3) can be used as a sensitizer for a blue TTA emitter, 9,10-Bis(2-naphthyl)anthraces (ADN). In a conventional Alq3-based OLED, when the electron and hole coming from cathode and anode recombined at Alq3 as the recombination layer, 25% of singlet and 75% of triplet were generated. All triplet exciton experienced non-radiative recombination, which resulted in low efficiency due to the poor reverse intersystem crossing (RISC) rate. On the other hand, in TTAUC-OLED, triplet exciton of Alq3 (ET=2.0 eV) transferred the energy to the triplet of ADN (ET=1.67 eV) via Dexter energy transfer and two of them fused into one singlet (ES=2.83 eV) with blue emission. This recycled the useless triplet exciton and resulted in a higher external quantum efficiency (EQE) for TTAUC-OLED (2.1%) compared to the Alq3 (1.2%) and ADN (1.67%) control devices. Moreover, the recombination zone was shifted from ADN to Alq3, the operation lifetime of blue component can be increased by 3x times longer than the ADN control device. From transient electroluminescence (TrEL) measurement, Alq3-control device showed a fast decay within 1us which implied only singlet exciton involved. For the TTAUC-OLED, blue emission showed only delayed component which meant the emission came from only TTA process without direct recombination.

Organic light-emitting diodes (OLEDs) have been successfully applied as displays and also recognized as a next-generation lighting technology because their several advantages such as self-emission, high luminous efficiency, full-color capability, wide viewing angle, high contrast, low power consumption, low weight, large area manufacture, transparence and flexibility. Now, the red and green phosphorescent OLEDs are qualified for the commercial products. The bottleneck still is the blue OLED. Currently, the high efficiency (100% internal quantum efficiency, and over 20% external quantum efficiency, EQE) blue OLED can be achieved using phosphorescent and thermal activated delay fluorescent (TADF) emitters, which were the crucial factor to determine color purity, efficiency, and lifetime of device. Beside the emitters, the other important factor is the host material. In this talk, we synthesized several novel carbazole-based, benzimidazole-based, and their combined derivers to be the universal hosts with wide energy bandgap for red, green, blue phosphorescent emitters and also applied for green and blue TADF emitters. These novel host materials could be classified as electron transport, hole transport, and bipolar. The carrier dynamics in OLEDs with these host materials were investigated by probing the position of main recombination zone and optimizing the efficiency performance. With increasing electron mobility of host material, the main carrier recombination zone in emitting layer was moved from the ETL side to the HTL side. Finally, the high EQE of over 30% was achieved in green and blue phosphorescent and TADF OLEDs with our host system. In addition, the operational lifetime was also improved by using our host system, comparing that of OLED with commercial mCP host.

In this study, we demonstrated a blue phosphorescent organic light-emitting diode (BPOLED) based on a host with two carbazole and one trizole (2CbzTAZ) moiety, 9,9′-(2-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)-1,3-phenylene)bis(9H-carbazole), that exhibits bipolar transport characteristics. Compared with the devices with a carbazole host (N,N’-dicarbazolyl-3,5-benzene, (mCP)), triazole host (3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, (TAZ)), or a physical mixture of mCP:TAZ, which exhibit hole, electron, and bipolar transport characteristics, respectively, the BPOLED with the bipolar 2CbzTAZ host exhibited the lowest driving voltage (6.55 V at 10 mA/cm2), the highest efficiencies (maximum current efficiency of 52.25 cd/A and external quantum efficiency of 23.89%), and the lowest efficiency roll-off, when doped with bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) as blue phosphor. From analyses of light leakage of the emission spectra of electroluminescence, transient electroluminescence, and partially doped OLEDs, it was found that the recombination zone was well confined inside the emitting layer and the recombination rate was most efficient in a 2CbzTAZ-based OLED. For the other cases using mCP, TAZ, and mCP:TAZ as hosts, electrons and holes transported with different routes that resulted in carrier accumulation on different organic molecules and lowered the recombination rate.

Multifunctional co-poly(amic acid) (PAmA) containing pyrene and carboxylic acid side-chains is developed as a binder for the recycled kerf-loss Si-Ni-SiC composite anode. The capacity retention performance of the lithium-ion battery can be apparently enhanced. In a long-cycle test of 300 lithiation/delithiation cycles, 79% of capacity retention is achieved. In considering that the recycled kerf-loss Si sample contains 38 wt% inactive micro-sized SiC abrasive particles, the achieved capacity of 648 mAh g−1 is reasonably high in comparison to other reported values. Small anode thickness expansion of 43% is found in a 100 cycle test, reflecting that the use of the PAmA binder can create strong interconnection among the silicon particles, conductive carbons and copper electrode.

The novel ambipolar hosts of o-CbzBz and o-DiCbzBz contain carbazole and benzimidazole through an ortho-connection. The orthogonal conformations cause the triplet state to be confined at the carbazole units to secure efficient energy transfer. The phosphorescent organic light-emitting diodes (PhOLEDs) show a high current efficiency, power efficiency, and low efficiency roll-off. o-DiCbzBz can be used as a host for sky-blue, green, and orange-red PhOLEDs, giving 57.5, 78.4, and 60.3 cd/A, respectively.