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Introduction: Tribocatalysis, an emerging cutting‐edge technique that uses frictional mechanical energy to activate the catalytic operation of a reaction or material including nanomaterials has garnered the interest of the research community in recent times. Aim: This study aimed to critically review original research works directed toward tribocatalytic degradation of various hazardous dye pollutants. Notably, in this review, various nanomaterials and their composites with outstanding tailored degradation profiles are explored for their tribocatalytic degradation efficiency for various dye pollutants. In addition, the effect of various operating factors that are of importance to engineers, industries, and investors for optimization purposes was pragmatically discussed. Also, the effect of electron trapping and radical scavengers alongside the mechanism of tribocatalytic degradation was empirically analyzed. Results: From this work, it was found that the maximum tribocatalytic degradation efficiency was >80% in most cases at an optimum temperature of 20–40°C, time taken of 0.5‐48 hours, and stirring speed of 500‐1000rmp. It was discovered that magnetic stirring enhances the production of •OH, O2•, and h+ by the nanomaterials that are mechanistically responsible for the degradation of the dye pollutants. Also, it was revealed that expended tribocatalyst can be eluted mostly using H2O and can be reused up to 3–10 times while still sustaining degradation efficiency of >80% in most cases and this suggests the industrial scalability and eco‐friendliness potential of this approach. Conclusion: In the end, challenges and research gaps that can pave the way for method improvement and also serve as future research hotspots for researchers were presented. [ABSTRACT FROM AUTHOR]

Surface modification, including the anchoring of functional groups is a popular method to increase the photocatalytic activity of semiconductor photocatalysts. These species can trap excited electrons, thus prolonging the life of the charge carriers. N-containing functional groups are suitable for this purpose due to their high electron density. Here, we report a facile synthesis method for preparing interfacial N-based functional groups-modified and nitrogen-doped SrTiO3 photocatalysts. Among the modified samples (with 0.42–11.14 at.% nominal nitrogen content), the one with 7.71 at.% nitrogen showed 6.4 times higher photooxidation efficiency for phenol and 2.2 times better photoreduction efficiency for CO2 conversion than the unmodified SrTiO3 reference. Characterization results showed that using a low amount of nitrogen source resulted in low but measurable nitrogen doping, which did not significantly affect the photocatalytic activity. The formation of surface amine groups was significant even at lower initial nitrogen concentrations, while higher amounts of nitrogen source gradually resulted in the incorporation of nitrogen in higher amounts. Surface amine groups decreased the recombination of charge carriers, resulting in increased photocatalytic activity.

The threshold voltage (VT) is the most important parameter in semiconductor devices. To control the VT of the thin‐film transistors (TFTs), we propose heterojunction structure of p‐type Tellurium (Te) and n‐type Aluminum‐Doped Indium‐Zinc‐Tin‐Oxide (Al:IZTO) which acts as electron blocking layer and carrier transporting layer, respectively. We investigate the effect of adding the heterojunction layer on the Al:IZTO and demonstrate VT shift up to +20V by adjusting the thickness and single / double deposition of the heterojunction Te layer. [ABSTRACT FROM AUTHOR]

A single photon avalanche diode (SPAD) cell using N-channel extended-drain metal oxide semiconductor (N-EDMOS) is tested for its hot-carrier damage (HCD) resistance. The stressing gate-voltage (VGS) dependence is compared to hot-hole (HH) injection, positive bias temperature (PBT) instability and off-mode (VGS = 0). The goal was to check an accurate device lifetime extraction using accelerated DC to AC stressing by applying the quasi-static (QS) lifetime technique. N-EDMOS device is devoted to 3D bonding with CMOS imagers obtained by an optimized process with an effective gate-length Leff = 0.25 µm and a SiO2 gate-oxide thickness Tox = 5 nm. The operating frequency is 10 MHz at maximum supply voltage VDDmax = 5.5 V. TCAD simulations are used to determine the real voltage and timing configurations for the device in a mixed structure of the SPAD cell. AC device lifetime is obtained using worst-case DC accelerating degradation, which is transferred by QS technique to the AC waveforms applied to N-EDMOS device. This allows us to accurately obtain the AC device lifetime as a function of the delay and load for a fixed pulse shape. It shows the predominance of the high energy hot-carriers involved in the first substrate current peak during transients. [ABSTRACT FROM AUTHOR]

In this theoretical work, we designed a series of two-dimensional (2D) Me–BNX systems by replacing the sp2-hybridized carbon atoms in Me–graphene with BN pairs. The Mg, Al, Si, P, Ti, and Ge elements were used as the X species to replace the sp3 carbon at the central position in the original Me–graphene template. The related 2D materials were investigated using density functional theory calculations. From the perspectives of energy, lattice dynamics, and mechanics, these Me–BNX systems are structurally stable. Interestingly, most Me–BNX possess very small Poisson's ratios, while four of them are even negative caused by the synergism of the mechanical and electronic effects. Some of the Me–BNX systems are semiconductors. Especially, the Me–BNMg and Me–BNAl systems have optimal band gaps of around 1.9 eV at the B3LYP level with a 30% hybridization. Importantly, the Me–BNAl and Me–BNP systems are spin-polarized due to the trapping of the unpaired electrons in Al and P atoms by the localized electric fields, although there is no transition metal element. Furthermore, the energy difference of the band gaps between the two spin states of Me–BNAl reaches approximately 3.4 eV. Therefore, the optimal band gap and significant gap difference of Me–BNAl imply its promising application potential for solar utilization and spintronics. [ABSTRACT FROM AUTHOR]

Inspired by its great success in the photovoltaic field, methylammonium lead iodide perovskite (MAPbI3) has recently been actively explored as photocatalysts in H2 evolution reactions. However, the practical application of MAPbI3 photocatalysts remains hampered by the intrinsically fast trapping and recombination of photogenerated charges. Herein, we propose a novel strategy of regulating the distribution of defective areas to promote charge‐transfer dynamics of MAPbI3 photocatalysts. By deliberately designing and synthesizing the MAPbI3 photocatalysts featuring a unique continuation of defective areas, we demonstrate that such a feature enables retardation of charge trapping and recombination via lengthening the charge‐transfer distance. As an outcome, such MAPbI3 photocatalysts turn out to achieve an impressive photocatalytic H2 evolution rate as high as 0.64 mmol ⋅ g−1 ⋅ h−1, one order of magnitude higher than that of the conventional MAPbI3 photocatalysts. This work establishes a new paradigm for controlling charge‐transfer dynamics in photocatalysis. [ABSTRACT FROM AUTHOR]

Understanding the nature of charge‐trapping defects in amorphous chalcogenide alloy‐based phase‐change memory materials is important for tailoring the development of multilevel memory devices with increased data storage density. Herein, hybrid density‐functional theory simulations have been employed to investigate electron‐ and hole‐trapping processes in melt‐quenched glassy models of four different Ge‐Sb‐Te compositions, namely, GeTe, Sb2Te3, GeTe4, and Ge2Sb2Te5. The calculations demonstrate that extra electrons and holes are spontaneously trapped, creating charge‐trapping centers in the bandgap of the amorphous materials. Over‐ and undercoordinated atoms, tetrahedral and "see‐saw" octahedral‐like geometries, fourfold rings, homopolar bonds, near‐linear triatomic configurations, and chain‐like motifs comprise the range of the defective atomic environments that have been identified in the structural patterns of the charge‐trapping sites inside the glassy networks. The results illustrate that charge trapping corresponds to an intrinsic property of the glassy Ge‐Sb‐Te systems, show the impact of electron and hole localization on the atomic bonding of these materials, and they may have important implications related to the operation of phase‐change electronic‐memory devices. [ABSTRACT FROM AUTHOR]

A single photon avalanche diode (SPAD) cell using N-channel extended-drain metal oxide semiconductor (N-EDMOS) is tested for its hot-carrier damage (HCD) resistance. The stressing gate-voltage (VGS) dependence is compared to hot-hole (HH) injection, positive bias temperature (PBT) instability and off-mode (VGS = 0). The goal was to check an accurate device lifetime extraction using accelerated DC to AC stressing by applying the quasi-static (QS) lifetime technique. N-EDMOS device is devoted to 3D bonding with CMOS imagers obtained by an optimized process with an effective gate-length Leff = 0.25 µm and a SiO2 gate-oxide thickness Tox = 5 nm. The operating frequency is 10 MHz at maximum supply voltage VDDmax = 5.5 V. TCAD simulations are used to determine the real voltage and timing configurations for the device in a mixed structure of the SPAD cell. AC device lifetime is obtained using worst-case DC accelerating degradation, which is transferred by QS technique to the AC waveforms applied to N-EDMOS device. This allows us to accurately obtain the AC device lifetime as a function of the delay and load for a fixed pulse shape. It shows the predominance of the high energy hot-carriers involved in the first substrate current peak during transients.

The photocurrent multiplication (PM) effect has been used to boost the device performance of polymer‐based photodetectors (PDs), but its origin is rarely addressed. In this study, the origins of the PM effect in polymer PDs based on the P3HT:PC71BM bulk heterojunction (BHJ) composite thin film, where P3HT is poly(3‐hexylthiophene), and PC71BM is [6,6]phenyl‐C71‐butyric acid methyl ester, through both computational simulation and experimental investigation are reported. Systematic studies indicate that two key factors play an important role in the realization of the PM effect in polymer PDs. One factor is the work function of the metal electrode, and the other is the PC71BM aggregations at the interface between the P3HT:PC71BM BHJ composite thin film and the metal electrode. Moreover, the results from both experimental and computational simulation indicate that the values of the current density under light illumination minus the current density in the dark of polymer PDs are increased simultaneously along with the reduction of the thickness of the P3HT:PC71BM BHJ composite thin film. The results provide an understanding of the PM effect in polymer PDs and guidance for the development of high‐performance polymer PDs based on BHJ composite thin film. [ABSTRACT FROM AUTHOR]

Nowadays, in the literature, are formulas for induced charge fluctuations caused by the capturing of electrons and holes by traps. However, these formulas are valid only for the case of uniform ionization in the volume of a plane-parallel semiconductor detector, and formulas that take into account the attenuation of the X-ray flux when it penetrates the detector contain errors. In this work, the formulas for fluctuations of the induced charge on the electrodes of a plane-parallel semiconductor detector due to capturing of electrons and holes by traps, as well as due to spatial fluctuations of X-quantum interaction points, taking into account the attenuation of the X-rays flux, were obtained. The obtained formulas demonstrate the role of the covariance of charge fluctuations induced by electrons and holes at the detector electrodes due to random processes occurring in the detector when detecting X-rays. [ABSTRACT FROM AUTHOR]

The multilayer triboelectric nanogenerators (TENGs) are widely developed to enhance the output performance of device. However, these TENGs consisting of electron transfer, transport, trap layers toward a large volumetric charge density should be wearable and mass‐produced for commercialization. Thus, appropriate material selection in respective layers and fabrication method are crucial for the commercialization of multilayer TENG. This study presents all‐printed, sustainable wearable TENGs based on electron accumulation polymers (EAPs) with superior charge retention capability. The EAPs consisting of polytetrafluoroethylene (PTFE), carboxyl functionalized single‐walled carbon nanotubes (SWCNTs:COOH), and Ti3C2Tx (MXene) in a fluorinated polymer matrix, are used. Compared to the reference, the EAPs not only lead to approximately six times higher output performance (300 V and 40 µA) but also four times more sustainable charge retention capability (92%) for an hour. These are attributed to the three‐step electron‐trapping mechanism with electron transfer/transport from PTFE/SWCNT and electron trapping in MXene. In addition, TENGs with EAPs exhibit excellent mechanical stability and reliability with fascinating single‐electrode demonstrations. Finally, the TENG with EAPs can efficiently operate various portable electronics and pH monitoring systems with a pH sensor and a seven‐segment display in realistic scenarios. [ABSTRACT FROM AUTHOR]

In recent years, there is an ever-growing demand for providing sustainable power to flexible electronics, the Internet of Things, cloud computing and artificial intelligence. The additive manufacturing process can be used to develop energy harvesting devices with a variety of essential properties to fulfil this requirement. In the present work, flexible and transparent Triboelectric nanogenerator devices for energy harvesting applications are fabricated using Ionic liquid processed polyvinylidene fluoride and polyamide 6 by a material extrusion process. To improve the formation of the electroactive β- phase, PVDF was processed with varying ionic liquid content (5 %, 10 %, 15 %, 20 %), with studies conducted on its impact on dielectric properties and energy output of TENG devices. The triboelectric performance studies show that PVDF processed with 15 % of Ionic liquid provides the maximum peak output voltage of 180.5 V, short-circuit current of 16.5 µA and power density of 3.42 Wm−2. The addition of an Ionic Liquid to PVDF enhances the polar β-phase, dielectric constant, modify surface potential, and serves as a conductive medium for electrons trapped from the surface to the bulk material, leading to enhanced triboelectric charge density and improved performance of TENG devices. Similarly, the additive manufacturing method enables more rough surface contact between the two tribolayer through increased surface roughness and uniform layer printing, which leads to an increase in the charge transfer thereby boosting energy output performance. This study shows the feasibility of fabricating flexible TENG devices using Ionic liquid processed PVDF through additive manufacturing, with potential applications in energy harvesting. [Display omitted] • The TENG devices fabricated via additive manufacturing, using ionic liquid processed PVDF and Polyamide 6. • Ionic liquid which contains cation E mim + and anion Cl-, interacts with CF 2 and CH 2 dipoles, promoting β-phase formation in PVDF. • TENG produces a maximum output voltage of 180.5 V, short-circuit current of 16.5 µA, and a power density of 3.42 Wm−2. • The ionic liquid serves as a conductive medium for electron trapping. • 3D printing improves surface roughness, boosts charge transfer, and enhances TENG device power output. [ABSTRACT FROM AUTHOR]

Threshold voltage shift ($\Delta {V}_{\text{T}}$) under various current stress (CS) conditions need to be quantitatively studied in self-aligned top-gate amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs). Here, we propose a stretched-exponential function (SEF)-based $\Delta {V}_{\text{T}}$ model that can be applied to various combinations of ${V}_{\text{GS}}$ and ${V}_{\text{DS}}$. The proposed model indicates the characteristic electron trapping time constant $\tau _{1}$ is inversely proportional to (${V}_{\text{GS}} - {V}_{\text{T}}$). In contrast, the time constant $\tau _{2}$ is directly proportional to the square root of (${V}_{\text{DS}}+{V}_{\text{bi}}$), presumably due to the local donor creation by a lateral electric field. The proposed model was verified experimentally in various ${V}_{\text{GS}}$ and ${V}_{\text{DS}}$ configurations. Further, it is confirmed that the lateral electric field dominantly influences donor creation near the drain. [ABSTRACT FROM AUTHOR]

Surface modification, including the anchoring of functional groups is a popular method to increase the photocatalytic activity of semiconductor photocatalysts. These species can trap excited electrons, thus prolonging the life of the charge carriers. N-containing functional groups are suitable for this purpose due to their high electron density. Here, we report a facile synthesis method for preparing interfacial N-based functional groups-modified and nitrogen-doped SrTiO 3 photocatalysts. Among the modified samples (with 0.42-11.14 at.% nominal nitrogen content), the one with 7.71 at.% nitrogen showed 6.4 times higher photooxidation efficiency for phenol and 2.2 times better photoreduction efficiency for CO 2 conversion than the unmodified SrTiO 3 reference. Characterization results showed that using a low amount of nitrogen source resulted in low but measurable nitrogen doping, which did not significantly affect the photocatalytic activity. The formation of surface amine groups was significant even at lower initial nitrogen concentrations, while higher amounts of nitrogen source gradually resulted in the incorporation of nitrogen in higher amounts. Surface amine groups decreased the recombination of charge carriers, resulting in increased photocatalytic activity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (© 2024 The Authors.)

Currently, blue quantum‐dot light‐emitting diodes (QLEDs) remain the bottleneck limiting the development of QLED‐based applications. To achieve high‐performance blue QLEDs, poly‐N‐vinylcarbazole (PVK) is usually employed as the hole‐transport layer (HTL) to reduce the hole injection barrier. However, fabrication of efficient blue QLEDs with PVK HTL remains challenging and empirical/accidental. Here, it is demonstrated that PVK layer can trap electrons and hence resulting in low device efficiency. This is why the performance of blue QLEDs is highly dependent on the PVK batch received from the manufacturers. As an interlayer, ZnSe/ZnS quantum dots (QDs) are inserted between PVK and blue ZnCdSe/ZnS QD emitters. The resulted device presents an external quantum efficiency of 20.6% under 2920 cd m−2, enhanced by ≈35% compared with that of PVK‐alone device. The remarkable enhancement is owing to the QD interlayer that not only suppresses the electron trapping in PVK, increasing the probability of exciton recombination within the emissive layer, but also facilitates the hole injection, improving the charge balance in blue devices. [ABSTRACT FROM AUTHOR]

Electron trapping in HfO 2 -based MOS structures was studied through pulsed capacitance-voltage (C-V) technique. 10 nm HfO 2 layer was deposited by atomic layer deposition over a HF last treated Si substrate. The C-V curves were observed to shift to positive voltages driven by the positive applied voltage along the pulses, consistent with electron trapping due to tunneling transitions between the substrate and pre-existing defects within the oxide and the subsequent lattice relaxation through electron-phonon interaction. The dependences of the voltage shift for a given capacitance value (ΔV C) with stress bias and time, allowed to distinguish two mechanisms. An initial trapping process occurs for times shorter than the microsecond, probably associated with a thin non-stoichiometric SiO x interfacial layer, which is followed by a trapping process that starts after tens of μs and progressively slowed down, associated with traps within the HfO 2 layer. Numerical simulations yield for the HfO 2 traps an energy of 1.3 eV below the conduction band edge, decreasing exponentially with the distance from the Si interface with a characteristic length of 1.7 nm; and phonon and relaxation energies of 50 meV and 1 eV, respectively. These physical parameters are consistent with previous reports of electron trapping in HfO 2 layers deposited on a controlled interfacial layer, suggesting that trapping properties of defects inside the HfO 2 layer are insensitive to the treatment of the Si surface before HfO 2 deposition. On the other hand, the observed large initial trapping suggests that the non-controlled SiO x interfacial region is more defective than a controlled one. [Display omitted] • Electron trapping in HfO 2 layer deposited over HF last treated Si was studied. • A physics-based numerical model was employed to reproduce experimental results. • An initial trapping process is associated with a defective SiO x interfacial layer. • Trapping inside HfO 2 does not depend on the underlying interfacial layer. [ABSTRACT FROM AUTHOR]

In this study, we investigate the threshold voltage (${V} _{{{ \text {th}}}}$) instability of p-gate GaN HEMTs induced by gate bias. Experimental results are acquired by a custom pulse setup for two commercially available devices with an ohmic gate and a Schottky gate. A transient drain current change is observed, which corresponds to a shift of ${V} _{{{ \text {th}}}}$. A negative ${V} _{{{ \text {th}}}}$ instability is identified for the ohmic gate, a mostly positive for the Schottky gate that can also become negative depending on the gate bias voltage and duration. The impact of the gate-bias-induced ${V} _{{{ \text {th}}}}$ instability on the Schottky-gate device is significantly higher compared to the ohmic-gate device, but clearly noticeable at the nominal rated ON-state gate voltage for both devices. Electron depletion and trapping as well as hole accumulation and trapping are identified to cause this transient ${V} _{{{ \text {th}}}}$ instability. [ABSTRACT FROM AUTHOR]

The formation of nonlinear ion-acoustic waves is studied in a degenerate magnetoplasma accounting for quantized and trapped electrons. Relying on the reductive perturbation technique, a three-dimensional Zakharov–Kuznetsov (ZK) equation is derived, admitting a solitary wave solution with modified amplitude and width parameters. The stability of the ZK equation is also discussed using the k-expansion method. Subsequently, numerical analyses are carried out for plasma parameters of a dense stellar system involving white dwarf stars. It has been observed that the quantized magnetic field parameter η and degeneracy of electrons (determined by small temperature values T) affect the amplitude and width of the electric potential. The critical point at which the nature of the solitary structure changes from compressive to rarefaction is evaluated. Importantly, the growth rate of the instability associated with a three-dimensional ZK equation depends on the plasma parameters, and higher values of η and T tend to stabilize the solitons in quantized degenerate plasmas. The results of the present study may hold significance to comprehend the properties of wave propagation and instability growth in stellar and laboratory dense plasmas.

Flux ropes are a proposed site for particle energization during magnetic reconnection, with several mechanisms proposed. Here, Magnetospheric Multiscale mission observations of magnetic mirror structures on the edge of two ion‐scale magnetopause flux ropes are presented. Donut‐shaped features in the electron pitch angle distributions provide evidence for electron trapping in the structures. Furthermore, both events show trapping with extended 3D structure along the body of the flux rope. Potential formation mechanisms, such as the magnetic mirror instability, are examined and the evolutionary states of the structures are compared. Pressure and force analysis suggest that such structures could provide an important electron acceleration mechanism for magnetopause flux ropes, and for magnetic reconnection more generally.Key Points: Magnetospheric Multiscale observations show magnetic mirror structures on the edge of magnetopause flux ropesMirror structures trap electrons and have extended 3D structureEvolution of mirror structures could facilitate particle acceleration [ABSTRACT FROM AUTHOR]

Charge-trapping phenomena in radio-frequency (RF) power amplifiers (PAs) based on GaN high-electron-mobility transistor (HEMT) technology are understood to be responsible for the dynamic self-biasing behavior that leads to a seemingly intractable slow dynamic residual nonlinearity in communications applications. For this reason, and based on recent developments in the characterization and modeling of charge-trapping phenomena, in this article we demonstrate how the dynamic self-biasing behavior of GaN HEMT-based PAs can be characterized, modeled, and compensated. First, we describe a method for the accurate characterization of the capture and emission dynamics of charge-trapping phenomena using transient two-tone large-signal RF measurements. Then, we demonstrate that the accurate modeling of these phenomena is contingent on the capture process being described by a state-variable time constant, rather than a fixed near-instantaneous time constant as is typically assumed. Finally, we propose a fully analog electronic circuit that implements an approximation of the Shockley–Read–Hall (SRH) statistics-based physical model of charge trapping to compensate the dynamic self-biasing behavior of a 15 W GaN HEMT-based PA. [ABSTRACT FROM AUTHOR]

A novel trap mitigation mechanism using molecular additives, which relieves a characteristic early turn‐on voltage in a high‐mobility p‐type acene‐based small‐molecule organic semiconductor, when processed from hydrous solvents, is reported. The early turn‐on voltage is attributed to photo‐induced trapping, and additive incorporation is found to be very effective in suppressing this effect. Remarkably, the molecular additive does not disturb the charge transport properties of the small‐molecule semiconductor, but rather intercalates in the crystal structure. This novel technique allows for the solution‐processing of small molecular semiconductors from hydrous solvents, greatly simplifying manufacturing processes for large‐area electronics. Along with various electric and spectroscopic characterization techniques, simulations have given a deeper insight into the trap mitigation effect induced by the additive. [ABSTRACT FROM AUTHOR]

A true random‐number generator (TRNG) and a nonlinear feedback shift register (NFSR) are combined to create a new type of TRNG. This TRNG is based on the intrinsic stochasticity of threshold switching behavior in a Pt/HfO2/TiN memristor and an NFSR circuit. Considering the transition rate of the hopping process, the stochasticity of the delay time can be attributed to the phonon‐assisted hopping process. This novel TRNG passes all 15 National Institute of Standards and Technology randomness tests without post‐processing steps, proving its performance as a hardware security application. By combining the TRNG with the NFSR, the bit generation rate is further improved, allowing it to be used for high‐speed applications. [ABSTRACT FROM AUTHOR]

Pulsed radar amplifiers are known to present severe long-term memory effects in their pulse-to-pulse stability. These are usually attributed to electrothermal dynamics or to trapping effects originated in gallium-nitride (GaN) HEMTs. Expanding on our previous work where we devised a method for determining a suitable dynamic variation in the HEMT’s gate–source voltage for compensating these long-term memory effects in single-ended amplifiers, in this article, we present a feed-forward model to calculate this compensation signal in real-time pulsed radar applications. [ABSTRACT FROM AUTHOR]

Despite the significant advancement in the efficiency of perovskite light emitting diodes (PeLEDs), the issue of recombination-induced hysteresis during the ions migration has not been adequately addressed. This hysteresis behavior primarily arises from the slow redistribution of ions and their corresponding vacancies during the voltage sweeps. Here, our focus is on the trapping characteristics of ionic defects, which leads to the non-radiative recombination of charge carriers. We investigate the impact of various parameters, such as trapping cation energy, capturing coefficient, ion mobility, and scan rate on the hysteresis behavior observed in the J-V characteristics of device. Moreover, our results provide a framework for examining the relationship between mobile ions and charge carrier, implying that for better understanding of ions migration-induced field screening and carrier redistribution, it is crucial to consider the interplay of ions with charge carriers as a potential factor contributing to J-V hysteresis in the modeling of PeLEDs. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the threshold voltage shift characteristics of bottom-gate amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) under a wide range of positive stress voltages. We investigated four mechanisms: electron trapping at the gate insulator layer by a vertical electric field, electron trapping at the drain-side GI layer by hot-carrier injection, hole trapping at the source-side etch-stop layer by impact ionization, and donor-like state creation in the drain-side IGZO layer by a lateral electric field. To accurately analyze each mechanism, the local threshold voltages of the source and drain sides were measured by forward and reverse read-out. By using contour maps of the threshold voltage shift, we investigated which mechanism was dominant in various gate and drain stress voltage pairs. In addition, we investigated the effect of the oxygen content of the IGZO layer on the positive stress-induced threshold voltage shift. For oxygen-rich devices and oxygen-poor devices, the threshold voltage shift as well as the change in the density of states were analyzed.

A 3D flower-like mesoporous Ce doped ZnO composite composed of nanosheets was prepared by a facile, one-step wet chemical method at room temperature. It was found that the moderate Ce doping can improve the light absorption of ZnO. The photocatalytic activities of the samples were studied by the degradation of Rhodamine B (RhB) and phenol under stimulated sunlight. The 1% mole ratio of Ce doped ZnO composites (denoted as CZ1) showed higher photocatalytic performance than other samples, where 85.1% of RhB and 69.6% of phenol can be removed within 125 min and 120 min, respectively. The Ce4+ doped in the lattice of ZnO can act as the electron trapping sites, which effectively improve the electron-hole separation. In addition, it was also found the annealing temperature had effect on the morphology and structure of Ce doped ZnO. The photocatalytic performance can be further enhanced at proper annealing temperature (500 °C) due to the increase of ZnO crystallinity with maintained flower-like structure and the formation of CeO 2 -ZnO heterojunction at their tight interface promoting the separation of photogenerated electron-hole pairs. [ABSTRACT FROM AUTHOR]

A series of electropolymerizable cyclometallated IrIII complexes were synthesized and their electrochemical and photophysical properties studied. The triphenylamine electropolymerizable fragment was introduced by using triphenylamine‐2‐phenylpyridine and, respectively, triphenylamine‐benzothiazole as cyclometalated ligands. The coordination sphere was completed by two differently substituted β‐ketoiminate ligands deriving from the condensation of acetylacetone or hexafluoroacetylacetone with para‐bromoaniline. The influence of the ‐CH3/‐CF3 substitution to the electrochemical and photophysical properties was investigated. Both complexes with CH3 substituted β‐ketoiminate were emissive in solution and in solid state. Highly stable films were electrodeposited onto ITO coated glass substrates. Their emission was quenched by electron trapping within the polymeric network as proven by electrochemical studies. The ‐CF3 substitution of the β‐ketoiminate leads instead to the quenching of the emission and inhibits electropolymerization. [ABSTRACT FROM AUTHOR]

The threshold voltage (${V} _{\text {TH}}$) instability of p-GaN/AlGaN/GaN HEMTs was investigated under forward gate stress. A unique bidirectional ${V} _{\text {TH}}$ shift ($\Delta {V}_{\text {TH}}$) with the critical gate voltage (${V} _{\text {G}}$) of 6 V was observed. The carrier transport mechanisms underlying the $\Delta {V} _{\text {TH}}$ were extensively investigated through the voltage-dependent, time-resolved, and temperature-dependent gate current. The gate current is decomposed into electron and hole current in three distinct regions with respect to ${V} _{\text {G}}$ , which are off-state for ${V} _{\text {G}} < {1.2}$ V (${V} _{\text {TH}}$), on-state for $1.2~{V} < {V}_{\text {G}} < {5}$ V and “gate-injected” region for ${V} _{\text {G}}> {5}$ V. In off-state, the electrons were thermally activated and transport towards the gate, while electron-trapping governed by the space charge limited conduction (SCLC) in AlGaN barrier was observed in on-state and “gate-injected” region. Such an electron-trapping effect results in the positive ${V} _{\text {TH}}$ shift for ${V} _{\text {G}} < {6}$ V. Meanwhile, the marginal hole transport from gate by thermal activation was also captured by gate current, which features negligible impact on ${V} _{\text {TH}}$. However, for ${V} _{\text {G}}> {6}$ V, a drastic hole injection triggered by high ${V} _{\text {G}}$ takes place that causes subsequent hole-trapping in AlGaN barrier and hole-injection into GaN buffer. The injected holes enhance the positive charge in the gate region and turned the positively shifted ${V} _{\text {TH}}$ into a negative shift. [ABSTRACT FROM AUTHOR]

Highlights • A unified explanation is proposed to consistently explain the two-step degradation of a-IGZO TFTs under DC PBTI stress without or with different stress V ds. • For PBTI stress without stress V ds , the initial negative V th shift is believed to be induced by donor-like defect states corresponding to H 2 O molecule and intrinsic defects. • For PBTI stress with stress V ds , the negative shift is believed to be induced by donor-like defect states corresponding to oxygen vacancies. The gate-bias-induced electron trapping mechanism is responsible for the positive V th shift. Abstract A unified explanation is proposed to consistently explain the two-step degradation of amorphous InGaZnO (a-IGZO) thin film transistors (TFTs) under DC positive bias temperature instability (PBTI) stress without or with different drain stress voltages (V ds). For PBTI stress without stress V ds , this initial negative V th shift is believed to be induced by donor-like defect states corresponding to H 2 O molecule and intrinsic defects, while for PBTI stress with stress V ds , the negative shift is believed to be induced by donor-like defect states corresponding to oxygen vacancies. The gate-bias-induced electron trapping mechanism is responsible for positive V th shift. These transitions from negative to positive V th shift are resulted from the competition between the donor-like states creation and electron trapping. [ABSTRACT FROM AUTHOR]

The characteristics of dust ion‐acoustic waves (DIAWs) that are excited because of streaming ions and hot q‐non‐extensive electrons obeying a vortex‐like distribution are investigated. By exploiting a pseudo‐potential technique, we have derived an energy integral equation. The presence of non‐extensive q‐distributed hot trapped electrons and a streaming ion beam has been shown to influence soliton structure quite significantly. The evolution of the soliton‐like perturbations in complex plasmas, taking into account the dissipation processes, are also investigated, obtained by numerically solving the modified Schamel, equation whose widths are dependant on electron trapping efficiency β. Our illustrations indicate that compressive DIAWs develop in this plasma. As the plasmas in reality have a relative flow, such an analysis can be used to understand the DIA solitary structures observed in the mesospheric noctilucent clouds. [ABSTRACT FROM AUTHOR]

In this paper, we describe a hybrid analog/digital linearization scheme for GaN high-electron-mobility transistor (HEMT)-based power amplifiers that consists of a novel analog feedforward circuit and a conventional generalized memory polynomial (GMP) digital predistorter (DPD). The analog circuit implements a nonlinear filter that compensates the long-term memory effects observed in GaN HEMTs due to the self-biasing behavior caused by electron-trapping phenomena. Experimental tests demonstrate that this linearization scheme achieves a level of intermodulation distortion 6.8 dB better than what can be achieved with just the use of the GMP DPD. This level of distortion is in compliance with the linearity specifications for multicarrier Global System for Mobile communications base station transmitters. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C 3 N 4 ) is a promising visible-light-driven photocatalyst for solar energy conversion by splitting water into H 2 . However, the photocatalytic performance of g-C 3 N 4 is not sufficient because of low surface area and fast recombination of charge carriers. Here, g-C 3 N 4 with nanosheet structure was prepared by using mixture of melamine (M) and urea (U) as the precursors for the photocatalytic H 2 production from water. The use of U increased the surface area with mesoporous structure and defects of nitrogen vacancies acting as trap states in g-C 3 N 4 . The as-obtained g-C 3 N 4 -M 1 U 2 (1 and 2 denote the weight ratios of M and U, respectively) exhibited the photocatalytic H 2 production rate of 3.1 mmol g −1  h −1 under λ ≥ 400 nm light irradiation and apparent quantum efficiency (AQE) of 74% at λ = 400 nm. Single-particle photoluminescence (PL), originated from charge recombination of photogenerated charge carriers, showed longer lifetime of charge carriers in g-C 3 N 4 -M 1 U 2 than that in g-C 3 N 4 -M. Femtosecond time-resolved diffuse reflectance measurement was performed to observe the photogenerated electrons trapping in g-C 3 N 4 -M x U y . The results show that the electron trapping by the defects as trap states occurs faster in g-C 3 N 4 -M x U y than in g-C 3 N 4 -M. It is suggested that the use of U increases the defects as electron trap states, leading efficient photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

Pharmaceutical contaminations in the water resources becomes very serious global environmental issue. Therefore, these pharmaceutical molecules should be removed from the water resources. In the current work, 3D/3D/2D-Co 3 O 4 /TiO 2 /rGO nanostructures were synthesized through a facile self-assembly-assisted solvothermal method for an effective removal of pharmaceutical contaminations. The nanocomposite was finely optimized through the response surface methodology (RSM) technique with different initial reaction parameters and different molar ratios. Various characterization techniques were used to understand the physical and chemical properties of 3D/3D/2D heterojunction and its photocatalytic performance. The degradation performance of ternary nanostructure was rapidly increased owing formation of 3D/3D/2D heterojunction nanochannels. The 2D-rGO nanosheets play an essential role in trapping photoexcited charge carriers to reduce the recombination process rapidly as confirmed by photoluminescence analysis. Tetracycline and ibuprofen were used as model carcinogen molecules to examine the degradation efficiency of Co 3 O 4 /TiO 2 /rGO under visible light irradiation using halogen lamp. The intermediates produced during the degradation process were studied using LC-TOF/MS analysis. The pharmaceutical molecules tetracycline and ibuprofen follows pseudo first order kinetics model. The photodegradation results show that the 6:4 M ratio of Co 3 O 4 :TiO 2 with 5% rGO exhibits 12.4 times and 12.3 higher degradation ability than pristine Co 3 O 4 nanostructures against tetracycline and ibuprofen, respectively. These results shows high efficiency of Co 3 O 4 /TiO 2 /rGO composite against the degradation of tetracycline and ibuprofen. • Co 3 O 4 /TiO 2 /rGO nanocomposite was synthesized through facile solvothermal method. • The efficient transportation of electron-hole pairs is observed in nanocomposite. • Enhancement in visible light absorption and suppression of e−-h+ recombination. • High degradation stability and recyclability of Co 3 O 4 /TiO 2 /rGO nanocomposite. [ABSTRACT FROM AUTHOR]

• Wide-bandgap CdZnTe detectors used for gamma-ray detection can achieve high energy resolution at room temperature. • The properties of the crystal material are a key factor in determining the performance of semiconductor detectors. • We proposed a direct measurement method of the parameters describing electron transport properties. • Nonideal weighting potentials are considered to reduce systematic errors in the measurements. The single-polarity charge-sensing electrode is widely used in wide-bandgap room-temperature CdZnTe detectors; in such systems, the drift of electrons is the primary contribution to the induced signal at the anode. Thus, it is important to accurately evaluate the parameters that describe the electron transport properties because they affect the performance of detectors. This paper proposes a method to directly measure the electron mobility and their mean free drift time in a pixelated CdZnTe detector using a depth-sensitive technique. The presented method considers the effect of the nonideal weighting potential in an actual detector, which has not been accounted for in previously proposed methods. In addition, by fitting the cathode waveform to avoid the effect of the time–amplitude walk due to the trigger threshold, improved measurement accuracy of the electron drift parameters can be achieved. [ABSTRACT FROM AUTHOR]

Recently, one-transistor dynamic random-access memory (1T-DRAM) cells having a polysilicon body (poly-Si 1T-DRAM) have attracted attention as candidates to replace conventional one-transistor one-capacitor dynamic random-access memory (1T-1C DRAM). Poly-Si 1T-DRAM enables the cost-effective implementation of a silicon-on-insulator (SOI) structure and a three-dimensional (3D) stacked architecture for increasing integration density. However, studies on the transient characteristics of poly-Si 1T-DRAM are still lacking. In this paper, with TCAD simulation, we examine the differences between the memory mechanisms in poly-Si and silicon body 1T-DRAM. A silicon 1T-DRAM cell’s data state is determined by the number of holes stored in a floating body (FB), while a poly-Si 1T-DRAM cell’s state depends on the number of electrons trapped in its grain boundary (GB). This means that a poly-Si 1T-DRAM can perform memory operations by using GB as a storage region in thin body devices with a small FB area.