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Light‐emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P‐QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P‐QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non‐radiative recombination and possess high thermal stability. Here, we report 2,4,6‐Tris(3′‐(pyridine‐3‐yl) biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz, 3P) with strong electron‐withdrawing moieties of pyridine and triazine to modulate the performance of P‐QLEDs. Compared with commonly used 1,3,5‐Tris(1‐phenyl‐1H‐benzimidazol‐2‐yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non‐radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole‐blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P‐QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m−2, which is 151 % and about 11‐fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P‐QLEDs from the perspective of selective ETM. [ABSTRACT FROM AUTHOR]

Light‐emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P‐QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P‐QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non‐radiative recombination and possess high thermal stability. Here, we report 2,4,6‐Tris(3′‐(pyridine‐3‐yl) biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz, 3P) with strong electron‐withdrawing moieties of pyridine and triazine to modulate the performance of P‐QLEDs. Compared with commonly used 1,3,5‐Tris(1‐phenyl‐1H‐benzimidazol‐2‐yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non‐radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole‐blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P‐QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m−2, which is 151 % and about 11‐fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P‐QLEDs from the perspective of selective ETM. [ABSTRACT FROM AUTHOR]

As a critical component of electrostatic capacitors, the polymer dielectric directly affects the performance of the capacitor. In this work, Polycarbonate (PC)/Polyvinylidene fluoride (PVDF) asymmetric bilayer polymer dielectrics were prepared, and the influence of different polymer materials' barrier characteristics on various electrical properties of composite dielectrics was studied by changing the direction of applied electric fields. Research has found that the dielectric constant of a composite dielectric is between PVDF and PC (approximately 4.8 at 10 Hz) and is independent of the relative position of PVDF and PC in the dielectric. However, the relative position of PC and PVDF has a significant impact on the energy-storage characteristics of composite dielectrics. When PVDF comes into contact with the negative electrode, even though PC has a higher hole barrier, the composite dielectric can only withstand a maximum electric-field strength of 400 MV/m, which is much lower than the maximum electric-field strength that pure PC can withstand (520 MV/m), and it only achieves an energy-storage density of 3.7 J/cm3. When the PC comes into contact with the negative electrode, the high electron barrier of the PC effectively suppresses the injection of electrons at the electrode. It can withstand the same electric-field strength as PC (520 MV/m), achieving an energy-storage density of 5.48 J/cm3, which is 1.46 times that of pure PC and 1.64 times that of PVDF. This experiment effectively combined the advantages of PC and PVDF by utilizing the electron/hole barrier of polymer materials to obtain a fully organic dielectric with excellent energy-storage performance. [ABSTRACT FROM AUTHOR]

Metal halide perovskite semiconductors have demonstrated remarkable performance in light‐emitting‐diode applications in recent years. However, their potential application in other emerging optoelectronic devices, such as light‐emitting field‐effect transistors (LEFETs) is impeded by poor luminous efficiency due to inefficient charge injection. Here, an n‐type MgZnInO (MIZO) as the channel layer is synthesized to achieve efficient electron injection in perovskite LEFETs. These findings indicate that the incorporation of Mg not only suppresses the generation of oxygen vacancies but also optimizes the energy level alignment. These synergistic effects reduce non‐radiative recombination and improve interfacial charge transport. Consequently, the MIZO‐based perovskite LEFETs exhibit an improvement in threshold voltage, subthreshold swing, and field‐effect mobility. The electroluminescence performance shows a peak external quantum efficiency (EQE) of 1.97% with a maximum brightness of 2.1 × 104 cd m−2, accompanied by low‐efficiency roll‐off (an EQE of 1.88% at the current density of 810 mA cm−2). To the best of the author's knowledge, this represents the best luminous efficiency reported for perovskite LEFETs to date. [ABSTRACT FROM AUTHOR]

Context: The new series of donor-π-acceptor dyes have been designed using pyridine derivatives as a donor group and thienothiophene as a π-spacer group, which were linked via 10 acceptor groups. The highest occupied molecular orbital energies range from − 6.177 to − 5.786 eV, whereas the lowest unoccupied molecular orbital energies range from − 2.181 to − 3.664 eV. A6 dye has smaller energy gap, lower hardness, higher electrophilicity index, and good photovoltaic performance than other sensitizers. The lowest dihedral angle is observed in A1, A2, A6, A7, and A8 which are appropriate for intramolecular charge transfer between the molecules. The A8 has higher light harvesting efficiency, which increases the photovoltaic efficiency of the designed dye. The A6, A7, and A8 dyes spend less time in the excited state, which means they emit photons more efficiently than other dyes. The interaction between donor to π-spacer (red line) parts of the dyes has the bonding interaction (positive), and π-spacer to acceptor (blue line) parts of the dyes have the bonding and antibonding (negative) behaviours. The dyes A5 and A9 have 305.79 and 357.71 times higher β0 values than urea (0.781 × 10−30 esu) molecules. The spectral properties of the A6 dye strongly affect the structural modification. Methods: The density functional theory (DFT) and time-dependent DFT (TD-DFT) approach B3LYP/6-311G (d,p) basic set were used to optimize the designed dyes. All the calculations are performed using Gauss view 6.0 and Gaussian 09 software. The density of state spectrum is plotted using Gauss sum 2.6. [ABSTRACT FROM AUTHOR]

Context: The world's energy and environmental requirements are changing due to rapid population growth and industrial growth, and solar cells can be used to meet these demands. Dye-sensitized solar cells (DSSCs) are solar cells in which energy conversion occurs via a process similar to photosynthesis in plants. DSSC development is still in its infancy. DSSCs can operate under cloudy conditions and indirect sunlight and have attracted considerable attention due to their low cost and high efficiency. We designed two metal-free TPA-based dyes (Dye2 and Dye3) based on the reference dye Mg207 (Dye1) by increasing the donor strength of the molecule, as such dyes have shown enhanced efficiency in DSSCs. Moreover, the triphenylamine (TPA) moiety has been demonstrated to be a good donor that prevents charge recombination. Intramolecular charge transfer (ICT) from the donor to acceptor moiety was found in the sensitizers, and electrons were promoted to the conduction band (CB) of the TiO2 semiconductor. The negative binding energy of the dye@TiO2 clusters indicated that dye adsorption on the semiconductor surface was stable. The double donor increased the electron injection and electronic coupling constants in Dye2 and Dye3, indicating that these newly designed dyes have superior charge injection capacity. Accordingly, the efficiencies of DSSCs with Dye2 and Dye3 were 9.77% and 9.62%, respectively, and substitution with the TPA unit at the -R1 and -R2 positions in Dye1 resulted in better power conversion compared to the parent compound (9.09%). Increased donor strength improved photovoltaic performance by increasing current density and light-harvesting efficiency. This is a good molecular design approach for preparing targeted donor- π -acceptor (D- π -A) organic dyes with high DSSC efficiency. Methods: To predict the charge transport and optoelectronic characteristics of the TPA dyes, quantum chemical calculations were carried out using Gaussian16. The ground-state (S0) optimized geometries of the sensitizers were computed by utilizing DFT at the B3LYP/6-31G** level. The absorption spectra (λ max) were computed by employing TD-DFT with various functionals (B3LYP, PBE1PBE, CAM-B3LYP, and BHandHLYP) in the gas and solvent (DCM) phases. Among the studied functionals, BHandHLYP was found to be best at successfully reproducing the experimental data. Thus, the absorption spectra of the newly designed dyes and dye@TiO2 were calculated at the BHandHLYP/6-31G** level. The dye@TiO2 cluster optimizations were carried out at the B3LYP/6-31G**(LANL2DZ) level. [ABSTRACT FROM AUTHOR]

Inorganic perovskite quantum dots (QDs) have garnered significant attention due to their outstanding optical properties. However, perovskite quantum dot light‐emitting diodes (Pe‐QLEDs) still face challenges related to their fluorescence efficiency and electron injection. First, the electron transport layer (ETL) leads to severe non‐radiative recombination due to fluorescence quenching in CsPbI3 QDs. Second, there is an electron injection imbalance resulting from low electron injection efficiency, leading to reduced non‐radiative recombination and external quantum efficiency. To address these issues, this study introduces two interface layer materials with different electron affinities, 1,3,5‐Tris(3‐pyridyl‐3‐phenyl)benzene (TmPyPB) and 2,4,6‐Tris(3′‐(pyridine‐3‐yl)biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz). These materials not only passivated defects on the surface of CsPbI3 QDs films but also effectively prevented the fluorescence quenching of CsPbI3 QDs by the PO‐T2T (ETL). TmPPPyTz, with a relatively lower LUMO energy level, further improved energy level matching, significantly enhancing electron injection efficiency. Ultimately, using interface engineering with the TmPPPyTz interface layer, the devices achieved an outstanding 25.80% champion‐level external quantum efficiency (EQE) for Pe‐QLEDs with only a sub‐bandgap voltage of 1.7 V and half‐life (T50) is 17.99 h at 100 nits. This research provided an effective method to enhance the performance of CsPbI3 Pe‐QLEDs, addressing long‐standing issues inhibiting their efficiency. [ABSTRACT FROM AUTHOR]

A dye-sensitized solar cell (DSSC) has been fabricated with a photoanode made with silver-decorated reduced graphene oxide over the layer of TiO2 nanoparticle coated over the FTO substrate using the Doctor Blade method. Due to the excellent electrical conductivity of silver decorated reduced graphene oxide and high adsorption of dye molecules, the cell parameters are enhanced. Three different concentrations of Ag decorated rGO (0.1% wt, 0.2% wt, and 0.3% wt) have been considered for this study and are compared with pure TiO2-based DSSC. It is confirmed that the 0.1% wt concentration of TiO2-Ag decorated rGO has shown better performance than the other concentrations as well as the pure TiO2 photoanode. Natural dyes having chlorophyll pigment have been used as sensitizers, and graphene-based counter electrodes are incorporated in all solar cells. DSSC of 0.1% wt concentration of TiO2-Ag decorated rGO has given short circuit current density, open circuit voltage, fill factor, and power conversion efficiency of 3.768 mA/cm2, 0.6518 V, 0.566, and 1.39%, respectively. The higher the concentration of Ag decorated rGO with TiO2, the lower the electron injection into the semiconductor oxide with increased band gap energy. In this experiment, we found that 0.1% wt concentration of TiO2-Ag decorated rGO has given a short power conversion efficiency of 1.39%, respectively. [ABSTRACT FROM AUTHOR]

The results of experimental studies of a discharge system based on a pulsed (200–400 μs, 5–25 Hz) high-current (5–30 A) planar magnetron discharge with a target diameter of 125 mm and additional electron injection from a vacuum arc discharge are presented. The electron injection into the magnetron discharge is carried out from the back of the sputtered target through the central aperture, which provides additional acceleration of the injected electrons in a cathode layer of the magnetron discharge and an increase in the energy efficiency of the discharge system. The mass-to-charge ion composition of the generated plasma has been studied in a range of operating pressure up to an extremely low level of 0.2 mTorr. The conditions to achieve a high fraction of target material ions in the magnetron plasma are defined, including those in the range of low operating pressure range, where the typical magnetron discharge is characterized by an increase of a working gas ion fraction, and transfers into a low-current form. [ABSTRACT FROM AUTHOR]

The features of the operation of a discharge system based on a planar magnetron with additional electron injection and a conical reflecting electrode are studied. Electrons are injected from a glow discharge with a hollow cathode placed on the back side of the target. The magnetron discharge target with a diameter of 125 mm was made of copper. The pressure of the working gas (argon) varied in the range from 3 to 0.5 mTorr. The discharges functioned in a continuous mode. The results of the effect of the reflecting electrode on the radial uniformity of the generated plasma, as well as the degree of its sputtering, are presented. The radial uniformity and the surface and phase structure of copper films formed when the working pressure decreases down to the lowest possible value (0.5 mTorr) are studied. [ABSTRACT FROM AUTHOR]

We carry out a numerical modeling of plasma injection with hot electrons into a thin layer of cold plasma in the presence of an external magnetic field. We show that the latter can significantly affect the emerging small-scale current filaments and sheets, even if it does not magnetize the particles and does not change the overall dynamics of the redistribution of the total plasma density in the process of injection. The effect observed depends on the orientation of the external magnetic field that is parallel to the plane that bounds the cold plasma layer, if the injection occurs from a narrow strip lying in this plane. In this situation, which corresponds to the ablation of a flat target by a femtosecond laser beam using cylindrical focusing, we study the evolution of the characteristic structures of the formed small-scale magnetic field. It is established that its generation is associated with instabilities of the anisotropic velocity distribution of electrons and that its value can be many times greater than the value of the external magnetic field. [ABSTRACT FROM AUTHOR]

Numerical simulation of the effect of a reflective electrode on the ion composition of the planar magnetron plasma, into the discharge region of which an electron beam with independently controlled electron current and energy is injected, is performed. The numerical simulation results indicate that in such a configuration, higher concentrations of ions of the working gas (argon) and the target cathode (copper) of the magnetron are achieved due to a higher degree of confinement in the region of the plasma generation of injected electrons due to their partial reflection and deflection in the retarding field of the reflective electrode. The simulation results agree satisfactorily with the experimental mass-charge composition of the plasma ions of such a magnetron. [ABSTRACT FROM AUTHOR]

A new photosensitizer 1-WS55 (dyad) based on two dyes with excellent properties, azulenocyanine (1) and WS55, is proposed at the density functional theory level (M06/def2-SVP). 1 is a dye having a broad NIR absorption (~ 1000 nm), and WS55 is a metal-free organic dye that presents a huge photoelectric conversion efficiency (PCE) of 9.5%. The dyad presents a panchromatic absorption along the UV–Vis-NIR region. It exhibits two intense Q bands (880, 926 nm) in the NIR region, one strong band (672 nm) in the visible region, and several bands in 300–600 nm. Charge transfer bands in the dyad from 1 to WS55 were found in the visible region, which favors the adsorption on an anatase TiO2 surface. The interaction energies dyad (dye)-TiO2 were calculated as a periodic system and corrected by the basis set superposition error. These show better adsorption for the dyad than fragments 1 and WS55. The electron injection calculated from the dye (dyad) to TiO2 suggests an efficient solar energy conversion because of ΔGinj > 0.2 eV. Additionally, calculations performed for the reorganization energy of electrons and holes indicate that the dyad presents the highest charge mobility. In summary, the dyad proposed 1-WS55 constitutes an excellent candidate to be used as a potential photosensitizer for the DSSCs. [ABSTRACT FROM AUTHOR]

The special features of the central injection of electrons from the emitter discharge plasma into the discharge system of a planar magnetron are studied. A glow discharge with a hollow cathode and a vacuum arc were used as an emitter discharge. The injection of electrons was carried out through the central hole in the magnetron target. The pressure of the working gas (argon) in the vacuum chamber was 0.05–0.09 Pa in the case of glow discharge emitter. The emitter glow discharge in the hollow cathode functioned in both low‑current continuous mode (10–100 mA) and high-current pulse mode (10–20 A, 25 microseconds, 1 Hz). The vacuum arc emitter operated in pulse mode (10–60 A, 200 microseconds, 1 Hz). Emission currents were measured for various configurations of the discharge system, including the conditions for the complete switching of the electronic component of the emitter current into the discharge system of the magnetron sputter. [ABSTRACT FROM AUTHOR]

• Chloride modification accelerate electron injection. • Chloride modification position is critical for ion migration. • The dense and smooth film facilitate better electrochemical behavior. • Supercapacitor had high cycle stability, maintaining 78% after 10,000 cycles. Ambipolar conducting polymer electrode materials exhibit a wide voltage window, contributing to fast development of high-energy–density storage devices. The doping levels of p-doped and n-doped in ambipolar conducting polymers determine the electrochemical performance of energy storage devices. However, n-doped materials always face low doping efficiency, caused by difficulty in electron injection and ion migration, thereby affecting specific capacitance and stability. In this study, two ambipolar conductive polymers were developed, in which the n-doped imine group was chlorinated to improve electron injection, and the mechanism of ion migration process was studied by changing the chlorination of different positions relative to the carbonyl group. The influence of chloride modification on n-doped electrochemical energy storage was thoroughly investigated. The results show that chloride modification can lower the lowest unoccupied molecular orbital (LUMO) energy level of the monomer and make electron injection easier. Interestingly, the chloride modification position not only affects the oxidation–reduction of the carbonyl, but also the binding of the carbonyl with lithium ions. If the chloride modification position is too close to the carbonyl, lithium-ion migration in ambipolar conducting polymer will be restricted, although electron injection is beneficial. Based on this design, the developed PEPCl conducting polymer exhibits excellent electrochemical performance, and the mechanism of chlorination modification of ambipolar polymer electrode materials is described. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dye aggregation on TiO 2 films could be regulated by the solvent of dye bath. • J-Aggregation induces higher long-wavelength absorption than H-aggregation. • Charge-separated dye aggregation has no adverse effects for electron injection. • J-Aggregation of charge-separated dye greatly enhanced the photocurrent of DSSCs. Aggregation of organic molecules plays a key role in determining the photoelectronic properties of various devices. However, the formation of aggregates is an outcome of complex synergistic effects of various intermolecular forces, and changes with the molecular structure and environment. Here we exploit the aggregation of two dyes with (MTPABT-Pyc) or without (MTPAcc) the nanosecond long-lived charge separation state and their effect on photovoltaic performance of dye-sensitized solar cells (DSSCs). Different solvent systems were selected to modulate the interactions between solvents and dye molecules for the effects on photophysical processes. Combining the experimental results on the solvent effect on dye aggregation with theoretical calculations reveals that MTPAcc inclines to form H -aggregation on the TiO 2 surface because of the decisive role of its molecular structure. The solvent regulation has a great impact on MTPABT-Pyc which can make aggregates transform between H -aggregation and J -aggregation. The effects of aggregation on the device performance of two dyes are completely opposite. High performance of MTPAcc depends on the co-adsorbent chenodeoxycholic acid, which could suppress the dye aggregation. In contrast, the aggregation of MTPABT-Pyc will not harm the charge separation and transportation processes in devices and shows a positive effect on the cell performance due to the aggregation exhibiting broader absorption bands. As the photocurrent contribution by the aggregation-induced long-wavelength absorption increases from 9% (H -aggregation) to 34% (J -aggregation), the short-circuit current (J sc) and the power conversion efficiency (PCE) of MTPABT-Pyc increased by 13% and 14%, respectively. These results pave a new way for taking full advantage of the aggregation of molecules to realize high-performance light-to-current conversion. [ABSTRACT FROM AUTHOR]

This study explores the challenges to photo-reforming sacrificial chemicals into beneficial by-products while improving photocatalytic activity in H 2 O 2 production by addressing several issues. The resorcinol-formaldehyde/graphitic carbon nitride composite (RF 0.2 GCN) with nanosheet-like RF morphology achieved a higher degree of surface-to-surface contact through -C-NH-CH 2 - and -NH-CH-OH than the nanosphere (RF 0.8 GCN). The RF 0.2 GCN produced H 2 O 2 at 325.2 µg g−1 s−1 in the presence of oxalic acid (OA) at pH 2.1 with apparent quantum yield (AQY) of 12.7 %. The conduction band position potential was +0.54 V NHE , which is thermodynamically unfavorable for H+/H 2 (E°: 0.00 V NHE) and O 2 / · O 2 - (E°: −0.046 V NHE) reaction and also inhibits the decomposition of H 2 O 2 (H 2 O 2 / · OH, E°: +0.39 V NHE). Furthermore, the decomposition of OA formed formic acid (FA) at 82 % selectivity and concurrent CO 2 · - formation could promote electron density in the conduction band via its electron-donating ability·H 2 O 2 was purified by isolating FA using anion exchange resin, and FA was recovered by desorption from the resin using HCl (pH 3). [Display omitted] • Nano-sheets stacking facilitates LLCT between the two photocatalysts. • Upcycling sacrificial chemicals into valuable chemical by-products. • Suitable band position for desirable direct O 2 → H 2 O 2 pathway. • Simultaneous production of hydrogen peroxide and formic acid. • Hydrogen peroxide and formic acid separation by ion-exchange resins. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) has attracted lots of attention to be used as interfacial materials in organic optoelectronic devices owing to its attractive properties. In this work, a series of transition-metal-doped ZnO thin films were prepared by using a facile aqueous solution process, thereafter these films were employed as electron injection layers (EILs) combined with the tris-(8-hydroxyquinoline) aluminum (Alq 3) emitting layer to construct the inverted organic light-emitting diodes (IOLEDs). The transition-metal-doped ZnO EIL-based IOLEDs demonstrate markedly improved device performance compared to the reference neat ZnO EIL-based IOLED. However, different transition-metal ions have much different doping effect on the device performance. CoCl 2 doped ZnO EIL based IOLED device possesss an optimal current efficiency of 5.52 cd A−1, which is increased about 40% compared to the device with the neat ZnO as EIL. The enhancement might be attributed to the increased electron mobility and favorable interfacial energy level alignment of the transition-metal doped ZnO EIL for more efficient electron injection. Our findings may provide a promising strategy to improve the electron injection properties of ZnO film in the OLED devices. • The transition-metal-doped ZnO films were used as the electron injection layers in OLEDs. • Transition-metal-doped ZnO films were prepared by using a facile aqueous solution process. • The transition-metal doping increased the electron injection efficiency of the OLEDs. [ABSTRACT FROM AUTHOR]

• Dual side transparent OLED devices with an Ag top cathode are achieved. • The efficient electron injection is fulfilled by inserting a 3 nm thick LiF layer. • Different from LiF/Al, the working mechanism of LiF/Ag cathode is tunneling mode. • A MoO 3 dielectric layer is capped on Ag cathode for light extraction. • Light extraction is greatly improved by the capping layer in terms of EL properties. Transparent organic light-emitting diodes (TrOLEDs) offer enormous promising applications in next-generation consumer electronic devices. Herein, TrOLEDs based on a silver (Ag) top cathode are fabricated via vacuum deposition. The semi-transparent and efficient Ag cathode has been fulfilled by combining the optimization of the thickness and deposition rate of Ag films with the modification of lithium fluoride (LiF) and molybdenum trioxide (MoO 3). The introduction of an optimal LiF layer is beneficial for electron injection, which could be explained by tunneling model due to its insulation property. And a MoO 3 dielectric layer is capped on Ag cathode for light extraction due to its high refraction index. The electroluminescent (EL) properties collected from the top Ag cathode side are remarkably improved by the capping MoO 3 dielectric layer while maintaining the EL performance collected from the bottom anode side. This work provides a meaningful guidance for the construction of TrOLEDs. [ABSTRACT FROM AUTHOR]

Highlights: By using a zinc ion-chelated polyethylenimine as electron injection layer, an inverted organic light-emitting device (OLED) was successfully prepared with an external quantum efficiency over 10% at a brightness of 45,610 cd m−2. The chelation between zinc ion and amine groups not only passivates polar amine groups, but also fuses separated electronic orbitals. The inverted OLED show an excellent air stability with an operating time of 541 h @ 1,000 cd m−2 without any protection. Here, this work presents an air-stable ultrabright inverted organic light-emitting device (OLED) by using zinc ion-chelated polyethylenimine (PEI) as electron injection layer. The zinc chelation is demonstrated to increase the conductivity of the PEI by three orders of magnitude and passivate the polar amine groups. With these physicochemical properties, the inverted OLED shows a record-high external quantum efficiency of 10.0% at a high brightness of 45,610 cd m−2 and can deliver a maximum brightness of 121,865 cd m−2. Besides, the inverted OLED is also demonstrated to possess an excellent air stability (humidity, 35%) with a half-brightness operating time of 541 h @ 1000 cd m−2 without any protection nor encapsulation. [ABSTRACT FROM AUTHOR]

2H MoS2 nanoflakes were exfoliated and surface-modified by amine (-NH2) groups in a simple three-step water-based approach. The NH2-modified MoS2 sheets were used as humidity sensitive layer for estimating various levels of relative humidity (RH) (10%–90%). The devices demonstrated a maximum response of 720% for 90% RH with ${t}_{{\text {response}}} =1.2$ s and ${t}_{{\text {recovery}}} =3.1$ s, respectively, when operated at 1 V. The device also displayed low hysteresis and good stability with a maximum error in response to ±5% when tested for 50 days. The device demonstrated a good response at lower RHs. To explain this enhancement of response, a novel “pseudo electron injection model” has been put forward. It established that the enhanced response was due to the increased electron transfer from the MoS2–NH2 system (with lone pairs) to the humidity layer resulting in an electron accumulation at the MoS2 layer, and thus lowering the conduction band minima (CBM) of the MoS2 system beneath. This accumulation amplified the device current significantly resulting in sensor performance enhancement. The CBM-lowering and electron population due to this pseudo electron injection were expressed as a function of the thickness of adsorbed humidity and the MoS2–NH2 layers, thereby finally expressing the enhanced response. From the models, extinction coefficients affecting CBM-lowering were calculated as $\alpha = -0.042$ eV and $\beta = -0.49$ eV nm−1 which supported the obtained results. [ABSTRACT FROM AUTHOR]

A 3D metal–organic framework (MOF) [(H3O)Zn(HCOO)3]∞ is developed as a highly efficient and air‐stable solution‐processed electron injection layer (s‐EIL). The [(H3O)Zn(HCOO)3]∞ film can be easily obtained by annealing a spin‐coated [Zn(HCOO)2(H2O)2]∞ film at 120 °C in air, which is facilely prepared by the reaction of ZnO powder with formic acid and the aqueous solution of ammonium. The un‐encapsulated electron‐only device with [(H3O)Zn(HCOO)3]∞ as the s‐EIL exhibits significantly enhanced electrical property and air stability, compared to that with vacuum‐evaporated Cs2CO3 as EIL. Such improvements can also be observed in inverted organic light‐emitting diodes. The device with [(H3O)Zn(HCOO)3]∞ s‐EIL demonstrates an operating voltage of 6.8 V at 1000 cd m−2, much lower than that with Cs2CO3 EIL (8.4 V). And the power efficiency is increased about 18%. The enhanced electron injection property of [(H3O)Zn(HCOO)3]∞‐modified indium–tin oxide (ITO) is attributed to its reduced work function compared to bare ITO, which is confirmed by ultraviolet photoelectron spectroscopy analysis. This approach is anticipated to be applied in other optoelectronic devices for efficient electron injection. [ABSTRACT FROM AUTHOR]

We present a model of the space charge limited (SCL) electron injection into a gap combined with trap-filled dielectric solid and vacuum or a gap combined with two different trap-filled dielectric solid. An optimized calculation method is proposed to calculate the SCL current density $J$ inside the gap under different gap voltages $V_{g}$. The $n$ scaling of $J$ – $V_{g}^{n}$ varies in a different range of $V_{g}$ , which is described as the Ohm regime, trap-limited regime, and SCL regime. It is found that the $n$ scaling is dependent on electron mobility and relative length scale between two media, which indicates that traps in the dielectric have a profound impact on SCL electron transport properties. [ABSTRACT FROM AUTHOR]

The organic field-effect transistors (OFETs) have developed rapidly in recent years. However, compared with the p-type OFETs, the n-type devices always show poorer performance due to their hard electron injection and low stability. It is necessary to further improve the charge injection properties of n-type OFETs. In this work, indium (In) layers, as an interlayer above contacts, were adopted for electron injection improvement in the n-type poly((N, N'-bis(2-octyldodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl)-alt-5, 5'-(2, 2'-bithiophene)) (N2200) OFETs. The injection barrier, such as Schottky barrier, at the metal/semiconductor interface was effectively weakened with the In interlayers thickness (TIn) increasing from 0 to 6 nm. The mechanism of electron injection changed from thermionic emission to tunneling, as the TIn reaching 6 nm. It results in a marked improvement in electrical properties for N2200 OFETs. The mobility increased from 0.09 to 0.29 cm2 ⋅ V−1 ⋅ s−1 while the subthreshold swing decreased from 2.7 to 0.8 V ⋅ dec−1 with the TIn. This work provides an efficient approach for the electron injection improvement in n-type OFETs. [ABSTRACT FROM AUTHOR]

It is shown by approximating the I–V characteristics of colloidal quantum dots of InSb and PbS narrow-gap semiconductors that, in the single-electron mode, electron transport in different voltage ranges is determined by one of the competing processes: emission from a quantum dot, injection into it, or transit through it with current limitation by the space charge. At voltages above 0.5 V, the I–V characteristics of single quantum dots contain current instability and dip portions, similar to the Coulomb gap. Qualitative and numerical comparative estimations suggest that, in the structure of a segregated set of quantum dots, single-electron transport and current limitation similar to the Coulomb blockade are observed. Light exposure during measurements of the I–V characteristics disrupts or enhances the effect and increases or decreases the current, depending on the excitation-radiation spectrum. [ABSTRACT FROM AUTHOR]

The dynamic random access memory (DRAM) disturb known as rowhammer (RH) has come to dominate the insecurity of computing systems worldwide. Several studies have concentrated on electron injection from a switching cell select transistor and capture by nearby storage node junctions as being the main mechanism for the effect. This article for the first time looks in-depth at RH from the point of view of both electron injection and capture, and capacitive crosstalk. The absence of such comprehensive studies at the silicon level in the literature can be attributed to its sensitive nature within the industry and highlights the difficulty of DRAM scaling. This review article, therefore, forms a broad foundation to extend understanding of this dangerous disturb mechanism and in so doing provides an informed view on the ability of future DRAM technologies to solve RH once and for all. [ABSTRACT FROM AUTHOR]

In this work, and experimentally propose inserting an SiO2 intermediate layer between the Ti and n-AlGaN layer to improve the electron injection efficiency. When the SiO2 intermediate layer is adopted, the SiO2 layer can share a part of the applied voltage and then weakens the surface depletion effect, which is confirmed by the capacitance–voltage measurement. Furthermore, the energy bending of the SiO2 layer pushes the affinity of Ti to be even higher than the conduction band of the Al0.60Ga0.40N layer, which then screens the Schottky barrier and favors the election injection. The influence of the thickness of the SiO2 intermediate layer is also investigated in this work. When the SiO2 layer becomes thick, the tunneling capability of the electrons will be significantly limited due to the increased tunnel region width, leading to increased forward voltage. [ABSTRACT FROM AUTHOR]

Porphyrin has excellent optical properties as required in solar cell applications, for example, high molar extinction coefficient and high quantum efficiency (≈80%). Excellent optical properties make porphyrin a good candidate as a photosensitizer, that is, in dye‐sensitized solar cells (DSSC). Nevertheless, porphyrins exhibit poor charge transfer resulting in poor cell performance. Poor charge transfer in porphyrins is due to the aggregation, low porphyrin adsorption, and weakly bound porphyrins on the TiO2 surface. Anchoring group attached to the porphyrin ring may play an important role to increase both charge transfer and porphyrin adsorption. This study adopts a strategy to increase the electron transfer from porphyrins to TiO2 by applying different anchoring groups. This strategy aims both to reduce the aggregation and to enhance the binding between porphyrin and TiO2 surface. The presence of methyl and carboxylic acid as the anchoring groups in the porphyrin system can increase the electronic coupling between the porphyrin and the TiO2 surface while also hindering the aggregation. Thus, the presence of anchoring groups improves the electron injection efficiency and cell performance. The type and position of the anchoring groups strongly contribute to the electron injection, thus is discussed in detail. [ABSTRACT FROM AUTHOR]

This article describes a plasma-generating system based on a non-self-sustained glow discharge with external electron injection and a hollow cathode in the shape of a tube with an internal diameter of 25 mm and a length of 300 mm made of stainless steel AISI 321. It is proved that the parameters of the non-self-sustained glow discharge under (0.2–1) Pa, (100–280) V, and (2–6) A depend on the auxiliary discharge current to a great extent, which is due to the determining influence of electrons injected from the auxiliary discharge plasma on the physical processes in the main discharge. The study of uniformity of temperature distribution on the hollow cathode walls has shown that it can reach ±10% of the average value and greatly depends not only on electric characteristics of the discharge but also on its working pressure. The study further demonstrates that such discharge can burn not only in elongated hollow rectilinear cathodes but also in hollow cathodes of a complex shape produced by welding two tubes at a 90% angle. The efficiency of using emitted electrons to sustain discharge and uniformity of temperature distribution on the walls is improved in the latter configuration. The discharge can be used for ion plasma nitriding of inner surfaces with treatment uniformity of ±8.5% of the average value for complex-shaped hollow cathodes. The mean thickness of the nitrided layer after 1 h of processing steel AISI 321 at 630 °C was $\approx 50~\mu \text{m}$ and the hardness of the nitrided layer exceeded the original value by $\approx 3$ times. [ABSTRACT FROM AUTHOR]

• Aromatic amines namely aniline and o-phenylenediamine capped TiO 2 was synthesized. • The life time of o-phenylenediamine/TiO 2 (T-2) composite was measured as 9.8 ms. • Photo-conversion efficiency of T-2 composite was found to be 9.84%. In this work, the efficiency of dye-sensitized solar cells (DSSC) was improved by capping TiO 2 with simple aromatic amines as a complexing agent. The aromatic amines, aniline and o-phenylenediamine capped TiO 2 composites were synthesized via hydrothermal route and used as scattering layer in dye-sensitized solar cell (DSSC). Markedly, the maximum photo-conversion efficiency of 9.84% was achieved with o-phenylenediamine capped-TiO 2 composite as o-phenylenediamine capped-TiO 2 showed higher reflectivity than the pristine TiO 2 , which is highly beneficial for reflecting the photons back to photoanode. In addition, the average life time of carriers in o-phenylenediamine capped-TiO 2 was found to be 9.8 ms, which was 2 times higher than the pristine TiO 2 (4.29 ms). [ABSTRACT FROM AUTHOR]

The injection process is one of the most crucial attributes that determine the final properties of the electron bunch in laser wakefield accelerators. Here, a new injection method is proposed and studied via particle-in-cell simulations for the typical parameters of the bubble regime. The injection is triggered by the laser beam that reaches the super-Gaussian profile in the focus. Such a beam undergoes rapid variations in its intensity distribution during the diffraction process. If this diffraction occurs in underdense plasma, consequent changes in the bubble structure activate a localized transverse injection process. The generated electron bunch is characterized by the short duration (~2 fs) and low transverse emittance (≤1 mm mrad) while maintaining relatively high charge (~0.2 nC). [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic properties required for photosensitizer of type-II core/shell QDs based on group II-VI semiconductor have been studies by first-principles DFT study. • Absorption range and electrons injection channels are often opposed to each other. • Electron-hole recombination is related to the strengths of interaction inside quantum dots. • (ZnTe) 6 (CdSe) 28 is the promising candidate as a feasible sensitizer. Type-II core/shell quantum dots (QDs) present a promising avenue for enhancing the stability and performance of quantum dot-sensitized solar cells (QDSSCs) by reducing charge carrier recombination through the mitigation of trap states and enhancing charge carrier separation. This paper reports first-principles studies on diverse core/shell QDs consisting of group II-VI elements, namely, ZnSe/CdS, ZnTe/CdSe, CdTe/CdS, ZnTe/CdS, CdTe/CdSe, ZnTe/CdTe and ZnTe/ZnSe. The geometric and electronic properties of these QDs were investigated using first-principles density functional theory. The core/shell structures of each quantum dot were optimized, and their energy stability was confirmed through vibrational frequency analysis. The highest occupied molecular orbital principally constituted by S, Se, or Te states, while the states from the shell form the lowest unoccupied molecular orbital. Calculations of optical absorptions and structure optimization after electron transition were conducted using time-dependent density functional theory. The feasibility of type-II core/shell QDs as sensitizers for QDSSCs was assessed by examining absorption spectrum, electron injection, and electron-hole recombination. The results demonstrated that ZnTe/CdSe not only effectively balanced the competition between absorption range and electron injection channels, but also provided a clear advantage in electron–hole separation. Consequently, ZnTe/CdSe holds significant promise as a viable sensitizer for QDSSCs. [ABSTRACT FROM AUTHOR]

A series of new organic dyes (T1 - T6) with nonfullerene acceptors have been theoretically designed around the chemical structure of tyrian purple (T) natural dye. For their ground state energy parameters, all the molecular geometries of those dyes were optimized by density functional theory (DFT) at its Becke, 3-parameter, Lee–Yang–Parr (B3LYP) level of theory with 6–31G+(d,p) basis sets. When benchmarking against several long range and range separated levels of theory, the Coulomb attenuated B3LYP (CAM-B3LYP) produced most accurate absorption maxima (λ max) value to that of T so it was further employed for further Time dependent DFT (TD-DFT) calculations. Frontier molecular orbitals (FMOs) with natural bond orbital (NBO) studies were used to study their intra molecular charge transfer (ICT). All of the dyes had their energy gaps (E g) values between their FMOs to range around 0.96–3.39 eV, whereas the starting reference dye had an E g of 1.30 eV. Their ionization potential (IP) values were ranged to be 3.07–7.25 eV which indicated their nature to loss electrons. The λ max in chloroform was marginally red-shifted with a value 600–625 from T (580 nm). The dye T6 showed its highest linear polarizability (< α >), and first and second order hyperpolarizabilities (β and γ). The synthetic experts can find the present research to design finest NLO materials for current and future uses. [Display omitted] • A study to highlight the importance of theoretical modeling to improve DSSCs performance. • Efficient utilization of Tyrian purple natural dye as a donor moiety. • Exploration of nonlinear optical (NLO) performance for new dyes. • The results shed insights into the design and optimization of organic DSSCS. [ABSTRACT FROM AUTHOR]

A novel trench insulated gate bipolar transistor (IGBT) with emitter dual injection (EDI-IGBT) is proposed and investigated. The device features the hybrid gate electrode and the tiny P-base. The hybrid gate is a combination of the conventional trench gate (TG) and the accumulation gate (AG). The TG contacts the P-base region and the N-drift region, while the AG contacts the N-drift region only. In the ON-state, the accumulation layer formed by the AG makes an additional accumulation injection in the emitter side, leading to the EDI phenomenon, and hence a low forward voltage drop (${V}_{ \mathrm{\scriptscriptstyle ON}}$). Simultaneously, the tiny P-base region reduces holes extracted by the reverse-biased p-base/n-drift junction, which also contributes to the reduction in ${V}_{ \mathrm{\scriptscriptstyle ON}}$. The simulation results show that the EDI-IGBT delivers comparable breakdown voltage and safe operating area (SOA) while featuring a 28% lower ${V}_{ \mathrm{\scriptscriptstyle ON}}$ , resulting in a reduction in total energy loss. Moreover, the existence of the AG suppresses the gate self-charging effect during the turn-on transient, leading to an improved turn-on performance. The excellent device performance, coupled with industry-standard IGBT-compatible fabrication process, makes the proposed EDI-IGBT a promising candidate for power switching applications. [ABSTRACT FROM AUTHOR]

Highlights • Imidazolium ionic liquids are utilized in electrolytes in dye-sensitized solar cells. • Cations in the ionic liquids are differently sized while bearing cyanoethyl group. • Bulky cations exhibit slow I 3 − diffusion and electron recombination. • But, unexpectedly, bulky cations suppress downward shift of TiO 2 conduction band. • This interesting result is closely associated with function of cyanoethyl group. Abstract Imidazoliums are commonly used ionic liquid cations in electrolyte in dye-sensitized solar cells (DSSCs). Here, the size effects of imidazolium cations bearing the cyanoethyl group on DSSC performance have been systematically investigated by introducing the different alkyl chains (C1–C12), by which size control is allowed in a range of 9–20 Å. The large cations slow down electron recombination and ion diffusion, but, unexpectedly, they suppress downward shift of TiO 2 conduction band significantly affecting on electron injection process. While all the cations used in this work demonstrate a better power conversion efficiency than that for the common imidazolium analogue, the interplay among the key processes results in the best performance with the medium-sized cation C4 (11 Å). This work paves a way for design of efficient electrolyte cations for photovoltaic devices. [ABSTRACT FROM AUTHOR]

• Comparison of structural features of vinyl coupled furan oligomers (VCFOs) with their thiophene derivatives (VCTOs) • Effect of substitution (–NO 2 , –CN and –COOH groups) on the optoelectronic properties is studied. • Absorption spectra and effect of solvation on the absorption spectra are evaluated. • Exciton binding energy, light harvesting efficiency, electron injection properties of VCFOs are studied. • Overall, 21 out of 23 designed VCFOs are found to show better optoelectronic characters. In the present study, twenty three new vinyl coupled furan oligomers (VCFOs) and four already reported thiophene oligomer (VCTOs) have been investigated for potential optoelectronic properties using DFT/TDDFT calculations. Frontier molecular orbital analysis shows that the HOMO-LUMO gap of VCFO7b is the lowest among all the candidates while VCFO1a bears the highest HOMO-LUMO gap. The VCFOs display high NLO activity, exergonic type electron injection characteristics and VCTO1&3 have low NLO activity & endergonic type electron injection characteristics. Furthermore, the study investigates the influence of heterocyclic unit in HOMO-LUMO gap, NLO activity, exciton binding energy, light harvesting efficiency, electron injection properties in VCFOs& VCTOs. As a whole 21 out of 23 designed VCFOs are found to have remarkable optoelectronic properties compared to their corresponding VCTOs. Overall, our results suggest that furan oligomer tunes the optoelectronic properties to a great extent than the thiophene oligomers. [ABSTRACT FROM AUTHOR]

• Electron acceleration by chirped echelon phase modulated (EPM) linearly polarised laser pulse in vacuum. • Enhancement in electron energy of about 2.5 GeV on account of suitable values of laser and magnetic field parameters. • Optimization of electron injection angle and magnetic field for enhanced electron acceleration. • Sensitiveness of chirp parameter and EPM gradient parameter on electron acceleration. Electron acceleration employing chirped echelon phase modulated (EPM) linearly polarised (LP) laser pulse in vacuum under the influence of axial magnetic field has been explored. Echelon supported laser pulse with phase modulation sustains the trapping of pre-accelerated electron in the most favourable phase. Furthermore, the addition of linear frequency chirp enlarges the electron laser interaction duration. Here, application of axial magnetic field serves a critical role in boosting the electron acceleration upto larger distances in the laser propagation direction. So, few MeV electron can be expedited up to GeV energy and retains it upto longer distances due to the collective influence of the frequency chirp and phase modulation. Effect of laser initial intensity, pulse duration, beam waist and electron injection is taken into consideration and optimized for enhanced energy gain. It is observed that the electron of initial energy ˜0.5 MeV can achieve energy of ˜2.5 GeV with I ∼ 1.38 × 10 20 W/cm2 due to chirped LP EPM laser pulse in the existence of suitable axial magnetic field (˜41.7 MG) at most favourable values of electron injection angle and EPM gradient parameter. [ABSTRACT FROM AUTHOR]

Tetra carboxyl Zn-phthalocyanine (TCTZnPc) with thiol linker is anchored onto titanium dioxide (TiO2) nanoparticles surface. The presence of a thiol group having lone pair of electrons further increase the electron donating capability of Zn-Phthalocyanine (ZnPc) derivative. TiO2 thin film is prepared and sensitized with the Zn- Phthalocyanine derivative. The type of aggregation of TCTZnPc in DMF and on TiO2 surface is studied from the steady-state absorption spectral techniques. The fluorescence spectral studies are carried out to analyze the quenching of ZnPc fluorescence on TiO2 surface. Further, the time-resolved fluorescence is carried out to confirm the electron injected from excited state TCTZnPc to the TiO2 nanoparticles conduction band. [ABSTRACT FROM AUTHOR]

Abstract In this study, we have demonstrated an inversion in the efficiency of TiO 2 and ZnO based dye sensitized solar cells for an organic sensitizer C343 and another Ru based sensitizer N719. Despite of faster electron injection from sensitizer C343 to TiO 2 than ZnO, the later shows a better photovoltaic efficiency. The higher photocurrent in C343-ZnO has been mechanistically justified by slower back electron recombination and higher dye loading obtained from open circuit potential decay, electrochemical impedance spectroscopy and absorption spectra of the sensitized photoanodes. The similar positive features are there for N719-ZnO system also. Still TiO 2 -N719 performs much better than ZnO-N719 in terms of device efficiency. We have found a signature of H-type aggregate formation of N719 dye on the ZnO photoanode surface which shows a higher energy absorption peak than the monomeric form of the dye in the diffuse reflectance mode absorption spectra of the photoanodes. These type of aggregates are unable to inject electrons into the semiconductor rather the dye aggregates can pull back the electrons from the CB of the ZnO and eventually undergoes ground state recombination. Ultrafast transient absorption spectroscopy and wavelength dependent photo-current spectra provide further insight into the effect of the dye aggregates on the photo-excited carrier dynamics which essentially reduces the light harvesting efficiency. Graphical abstract Inversion in efficiency of TiO 2 and ZnO photo-anode based DSSC depending on the choice of sensitizer. fx1 [ABSTRACT FROM AUTHOR]

Abstract In this work, highly efficient Tandem Organic Light Emitting Diode (OLED) based on planar organic charge generation layer (CGL) of C70/Pentacene is proposed. It is found that the proposed CGL generate charges as well as exhibits organic photovoltaic type behavior. In addition a very thin layer of Al/LiF and PEDOT:PSS is used as electron and hole injection layer respectively to further increase the transport of electrons and holes from CGL to emissive unit. The current efficiency and luminance of red tandem device is found to be 29 cd/A and 29010 cd/m2 at 20 mA/cm2 and 100 mA/cm2 respectively which is 1.855 times 1.856 times greater than that of single emitter device having current efficiency and luminance of 15.63 cd/A and 15630 cd/cm2 at the same current densities Generally, the turn on voltage of Tandem devices is almost double as compared to single unit device. But with the proposed CGL the turn on voltage of red tandem device is found to be 5.9 V which is less than double the turn on voltage of single unit device (3 V). Therefore, the effective charge generation and transport property of proposed CGL as well as remarkable high injection property of thin Al layer and PEDOT:PSS leads to the enhancement in the efficiency of tandem OLED. Highlights • An efficient Red Tandem OLED is designed using multilayers of C70/Pentacene/Al/LiF/PEDOT:PSS. • The optimized thickness is found to be 5 nm for both C70 and Pentacene. • Remarkable enhancement in both current efficiency and luminance is marked. • The turn –on voltage of tandem device is found to be less than twice the turn on voltage of single emitting device. [ABSTRACT FROM AUTHOR]

Abstract A method for enhancing trapped electrons in the laser wake-field acceleration in dilute plasma is proposed. In this method, a thin layer with near critical density is placed in front of the dilute plasma. Upon interaction of this layer with a short and high power laser pulse, a relatively large number of layer electrons are injected in dilute plasma. Some of these electrons are trapped in the wake-field of transmitted laser pulse. Particle in cell simulation is used to demonstrate this method. Simulations showed that in addition to increasing the number of trapped electrons, this mechanism also reduces the energy broadening. Highlights • A method for enhancing trapped electrons in the laser wake-field acceleration in dilute plasma is proposed. • In addition to increasing the number of trapped electrons, this mechanism also reduces the energy broadening. • Transverse emittance of the trapped electron bunch in this mechanism decreased. [ABSTRACT FROM AUTHOR]

Abstract We have explored the influence of supplementary electron injection on the operational parameters of a planar magnetron operating in repetitively pulsed mode (repetition rate 300 Hz, pulse duration 50–100 μs). The supplementary electron flux was provided from the plasma of an auxiliary hollow-cathode glow discharge and was accelerated directly into the magnetron cathode layer. We show that this supplementary electron injection eliminates magnetron ignition delay and increases the sputtered ion current from the magnetron plasma. Highlights • We have explored the influence of supplementary peripheral electron injection on the operational parameters of a planar magnetron operating in repetitively pulsed mode. • Electrons from the auxiliary hollow cathode discharge injected in the cathode layer of the magnetron discharge to an energy sufficient for effective gas ionization and formation of dense plasma near the sputter target. • It was shown that electron injection into the cathode layer of a pulsed magnetron discharge eliminates the ignition delay of the discharge and increases the magnetron current by about ten times the auxiliary current. • Electron injection also provides at least a twofold increase in the ion current to a collector located 15 cm from the target. [ABSTRACT FROM AUTHOR]

Abstract In plasma wakefield accelerators (e.g. AWAKE) the proton bunch self-modulation is seeded by the ionization front of a high-power laser pulse ionizing a vapour and by the resulting steep edge of the driving bunch profile inside the created plasma. In this paper, we present calculations in 2D linear theory for a concept of a different self-modulation seeding mechanism based on electron injection. The whole proton bunch propagates through a preformed plasma and the effective beam current is modulated by the external injection of a short electron bunch at the centre of the proton beam. The resulting sharp edge in the effective beam current in the trailing part of the proton bunch is driving large wakefields that can lead to a growth of the seeded self-modulation (SSM). Furthermore, we discuss the feasibility for applications in AWAKE Run 2. Highlights • Instead of seeding the proton-bunch SMI with a laser pulse, a short electron pulse can be used. • The steep rising edge of the effective charge density drives large amplitude wakefields. • The approach could be also a concept for Run 2 of the AWAKE-Experiment. [ABSTRACT FROM AUTHOR]

Transition metal oxide MnO x shows great potential in catalytic formaldehyde (HCHO) pollution degradation at room temperature, but it is difficult to effectively overcome the catalyst deactivation caused by the accumulation of intermediates. Hereon, a 3D conductive aerogel catalyst with cellulose nanofibers (CNF) skeleton supported MnO x nanoflowers and carbon black (CB) was prepared by freeze-drying. Based on the aerogel catalyst (MnO x /CB/CNF), an electro-injection-enhanced catalytic oxidation (EICO) strategy was proposed for HCHO degradation by promoting the formation lattice oxygen and reactive oxygen species O*. In the dynamic test (∼15 ppm at the weight hourly space velocity (WHSV) of 600000 mL/g MnO x ·h), the HCHO-to-CO 2 conversion efficiency of MnO x /CB/CNF by electro-injection can be enhanced to 76.27%, which is 26.4% higher than that without electro-injection, and the corresponding dynamic efficiency did not show a decreasing trend within 72 h. This proposed EICO strategy may realize the efficient and long-term pollutant degradation at room temperature. [Display omitted] • A three-dimensional aerogel catalyst MnO x /CB/CNF developed by freeze-drying. • Electro-injection-enhanced catalytic oxidation (EICO) strategy was proposed. • MnO x /CB/CNF shows excellent HCHO-to-CO 2 conversion efficiency of 76.27%. • EICO strategy promotes the conversion from O 2 to O* for enhancing catalytic activity. • EICO strategy enhances electrons' migration to inhibit catalysts' deactivation. [ABSTRACT FROM AUTHOR]

Dielectric laser acceleration (DLA) is new cheap and miniature laser acceleration scheme for acceleration of charged particles in the vicinity of the dielectric grating. In this paper injection characteristics of the electron bunch in a single fused silica grating based-structure with period λ g  = 260 nm is analyzed. Optimum aspect ratios of the grating width d/λg and height h /λg are obtained for the first surface mode harmonic. Simulation results of the injected electron dynamics show that there are two lateral positions ( y = 1.75 and y = 2.6 μm ) that the final electron energy is maximized. Existence of these two lateral positions increases flexibility of the injection process. In other words, injection can be made in the range of 1.4 < y(μm)<2.8 with two peaks of energy. Finally, injection of Gaussian electron bunch at each two optimum transverse positions is investigated by a numerical simulation. The initial momentum distribution is assumed to be Gaussian around the mean resonance velocity (β = λg/λ = 0.33). The initial longitudinal and transverse emittance of the electron bunch are selected as ε ||  = (δE/E) = 0.01 and, ε ⊥  = 3μmmrad respectively. The net energy gain in the fifty grating periods is 2.03 keV ( 2.225 keV ) and acceleration gradient for each injection position is about 160 MeV/m . [ABSTRACT FROM AUTHOR]

Injection of photoexcited electrons in the para-Ethyl Red dye to TiO 2 nanoparticles (Anatase, 40 nm diameter) is characterized by transient absorption on ultrafast time scales. This study focuses on understanding the effect of aprotic solvents on the injection rate. Transient absorption at 1900 cm −1 is probed following a 400 nm pulse which excites the electronic transition of p-ER adsorbed on TiO 2 through its carboxylic group. Measurements conducted in three different solvents show that electron injection lifetimes are in the 250–300 fs range but display a trend in correlation with solvent polarity: the electron injection lifetime is the shortest (257 fs) in acetonitrile followed by dichloromethane (271 fs) and chloroform (296 fs). This trend can be understood by using the Marcus theory in which the reorganization energy varies correspondingly in the three different solvents. This study shows that for aprotic solvents the one with the highest polarity facilitates the fastest electron injection. [ABSTRACT FROM AUTHOR]

Organic p-n junction (PNJ) composing of PEDOT:PSS(MoO 3 )/Bphen:Cs 2 CO 3 is introduced as electron injection layer (EIL) in the bottom-emission inverted organic light-emitting diodes (BIOLEDs). The devices with PNJ of PEDOT:PSS/Bphen:Cs 2 CO 3 or MoO 3 /Bphen:Cs 2 CO 3 as EIL achieve maximum current efficiency of 87.3 cd/A and 86.6 cd/A and power efficiency of 69.4 lm/W and 63 lm/W, respectively, which are higher than that79.8 cd/A and 60 lm/W of the device with the n-doping Bphen:Cs 2 CO 3 as EIL, and 51% and 55% improvement in the half operational lifetime. The injection of electrons from the interface of PNJ but not directly from the ITO cathode is more effectively comparison with conventional BIOLED with n-doped Bphen:Cs 2 CO 3 as EIL. Thus, reducing the charge accumulation between the electrode and the organic electron transport layer (ETL), moreover, the PNJ is able to control the injection equilibrium of the carriers, and improve the efficiency and stability of the device. [ABSTRACT FROM AUTHOR]

In this work, a quantum chemistry study was performed on the organometallic perovskites/organic hole transfer materials (HTMs) in the perovskite solar cells (PSCs) from the molecular engineering viewpoint. Density functional theory (DFT)/time-dependent DFT (TD-DFT) was applied to investigate the electronic structures/excited state properties of a series of the perovskites, ABX 3 (A=CH 3 NH 3 , NH 4 , CH(NH 2 ) 2 , B˭Ge, Sn, Pb, X=Cl, Br, I). On the basis of the energy level of the perovskites, HTMs and TiO 2 , all perovskite compounds demonstrate a positive response to the hole/electron injection in the PSCs. A high occupied molecular orbital (HOMO) density of the HTMs, TPB, NPB, TPD, MDA1, MDA2, MDA3, TH101 and V950, are distributed over the whole molecule, homogeneously, which makes the hole transfer more proper. Investigation of the photovoltaic properties of the PSCs shows that they are strongly influenced by the chloride anion. The theoretical trend of the exciton binding energy is according to: F- < NH 4 - < MA-based perovskites. Considering different analyses show that the rate of the electron injection rate constant and the light harvesting efficiency increase by an increase in the electron driving force and electronic chemical potential. The correlation of the band gaps and the chemical nature of the substitutions in the perovskites shows a collapse by an increase in the cation size. Finally, it is proposed that ASnCl 3 and AGeCl 3 perovskites are better candidates to be applied in the PSCs as photosensitizers due to an improved incident photon to current efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A new strategy was applied to construct heterostructural CdS/WO 3−x nanowires as stable non-elemental-metal (NEM) plasmonic photocatalyst. • NEM plasmonic CdS/WO 3−x nanowires exhibited greatly improved plasmonic photocatalytic hydrogen generation under visible/NIR light irradiation. • The high stability and activity of plasmonic photocatalyst CdS/WO 3−x is attributed to surface plasmon resonance of WO 3−x stabilized by continual injection of photoinduced electrons from CdS nanowires. Abstract To remedy the instability problem of the non-elemental-metal (NEM) plasmonic photocatalyst WO 3−x in aqueous solution, a novel strategy of photoinduced electron injection was applied to construct CdS/WO 3−x hetereostructures by growing WO 3−x on semiconductor CdS nanowires. Under visible/near-infrared light irradiation, the NEM plasmonic CdS/WO 3−x nanowires are highly stable and exhibit a much higher activity (1.60 mmol g−1 h−1) than do plasmonic WO 3−x (negligible amount) and semiconductor CdS (0.53 mmol g−1 h−1) in hydrogen generation. Wavelength dependent photocatalytic performance and Single-particle PL study demonstrate that photo-excited electrons on CdS continually inject into conduction band of WO 3−x , so that the surface plasmon resonance (SPR) of the NEM plasmonic photocatalyst WO 3−x is sustained while hot electrons generated by the SPR excitation are consumed for hydrogen generation. [ABSTRACT FROM AUTHOR]

Various photovoltaic parameters, i.e., electron injection (ΔGinject.), electronic coupling constants (|VRP|), light harvesting efficiencies (LHE), band alignment and electronic properties of five chalcone derivatives were studied by density functional theory (DFT) and time domain. The light was also shed on the effect of different electron donating groups and their strength intensity on the electronic and charge transfer properties. The balanced hole and electron reorganization energies for Comp 4 showed that it might have better ambipolar charge transfer in nature. The strong electron donating group(s) usually enhance(s) the ΔGinject. and |VRP| of chalcones as -N(CH3)2 > OCH3 > OH. Additionally, ΔGinject. and |VRP| of various substituted chalcone derivatives have been observed as trimethoxy > dimethoxy > monomethoxy. The greater electron donating ability of substituents is also favorable for the staggered band alignment. The superior ΔGinject. of all the studied chalcones than of the referenced compounds disclosed that the prior compounds would be proficient photovoltaic materials. [ABSTRACT FROM AUTHOR]