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Stream hydrology and water quality are highly interconnected and impacted by climate, land use and geology. We examined this connection using monitoring data from 2000 to 2019 for two streams with contrasting hydrological regimes—intermittent and regulated perennial—in subtropical Queensland, Australia. Our main objective was to evaluate relationships between groundwater levels, climate and flow regulation on the hydrology and water quality of an intermittent and a regulated subtropical stream. In intermittently flowing Lockyer Creek, flow was highly dependent on groundwater levels and occurred when the aquifer was recharged to elevations exceeding the upper 90‐percentile value. With 9.4% of the catchment area in irrigated horticulture, flow in Lockyer Creek was also likely to be reduced by drawdown of the aquifer for irrigation, with no flow for 30% to 81% of days over the observation period for stations in Lockyer Creek. In contrast, flow in the mid‐Brisbane River was continuous, regulated by discharge from a large upstream dam. Nutrient and suspended sediment concentrations in Lockyer Creek were generally higher than in the mid‐Brisbane River, likely associated with runoff from agricultural areas adjacent to the stream, while the upstream dam likely reduced the concentration and variability of nutrients and suspended sediment in the mid‐Brisbane River. During periods of low flow in the mid‐Brisbane River, longitudinal changes in nutrient and suspended sediment concentrations occurred, notably a significant decrease in total and dissolved inorganic nitrogen concentrations downstream (p < 0.05), indicating a possible effect of in‐stream algal uptake and denitrification. This study highlights the impact of human modifications on stream hydrology and water quality in the face of climate change. The findings can inform decision‐making on groundwater irrigation or dam release control for water security. [ABSTRACT FROM AUTHOR]

Conformal deposition of perovskite films on textured silicon surfaces using a dry process is crucial for producing high‐performance perovskite/silicon tandem solar cells. Herein, a radio frequency magnetron sputtering process is used with a PbI2 target to deposit precursor films. Iodination, thermal annealing, and dimethyl sulfoxide treatment are employed as posttreatment processes to improve the stoichiometry, crystallinity, and surface morphology of the PbI2 precursor. The precursor films are converted into perovskite using direct contact conversion process, and the interfacial and bulk properties are enhanced by methylamine vapor annealing to fabricate perovskite solar cells with a power conversion efficiency of 12.2%. Also, 18.3% efficiency is confirmed at a wider voltage sweep range, which suggests that further efficiency improvement is possible by removing defects inside the perovskite. Finally, uniform perovskite films are conformally deposited on a 25 cm2 textured silicon surface. With such high‐efficiency potential and conformality, the method of sputtering PbI2 can open a new way to fabricate perovskite/silicon tandem solar cells. [ABSTRACT FROM AUTHOR]

High‐performance continuous‐wave (CW) vertical‐cavity surface‐emitting lasers (VCSELs) rely on efficient thermal management for which top‐emitting 930 nm thin‐film VCSELs are integrated with a copper‐plated heatsink by using a double‐transfer technique, exhibiting the low‐power consumption, high‐power, and temperature‐stable VCSEL operation. In this study, the top‐emitting 930 nm thin‐film VCSEL structures, including the highly n‐doped GaAs ohmic and lattice‐matched InGaP etch‐stop layers, are epitaxially grown via a low‐pressure metalorganic chemical vapor deposition (LP‐MOCVD) system. The electrical and optical properties of the substrate‐removal thin‐film VCSELs are investigated under CW operation, compared to those of the bulk‐type VCSELs onto the n‐GaAs substrates. The differential series resistance (85.92 Ω) of the thin‐film VCSEL is 9.16% lower than 94.59 Ω of the bulk‐type VCSEL onto the n‐GaAs substrates. The thermal resistance (607 K W−1) of the thin‐film VCSEL is 46.33% lower than 1131 K W−1 of the bulk‐type VCSEL, by which the maximum peak power (11.70 mW) of the thin‐film VCSEL at 24 mA is 12.07% higher than 10.44 mW of the bulk‐type VCSEL at 22.40 mA under room temperature (25 °C). [ABSTRACT FROM AUTHOR]

The recent efficiency boosting of Cu(In,Ga)Se2 (CIGS) solar cells is undoubtedly triggered by heavy alkali postdeposition treatments (PDTs). However, the effects are not obvious under monolithically integrated CIGS modules where various current‐shunting sources can deteriorate the device performance. Herein, It is reported that KF PDT can effectively suppress the major shunting sources caused by P1 and P3 laser scribing for monolithic interconnection, reducing the cell‐to‐module (CTM) efficiency gap in CIGS photovoltaics. CIGS with NaF PDT exhibits nearly isotropic and high hole mobilities, causing a large CTM efficiency loss. CIGS with additional KF PDT, on the other hand, reveals much lower in‐plane hole mobility than the out‐of‐plane component, significantly increasing the P1 shunt resistance without exacerbating the photocarrier extraction in the active area. It is suggested that such anisotropic charge transport is due to carrier scattering by low‐conductivity phases at the CIGS grain boundaries. Furthermore, passivation of the front junction by KF PDT raises the tolerance to P3 scribing‐induced damage, increasing the P3 shunt resistance while preserving the junction property unlike the NaF PDT case. The work implies that the recent trend of employing heavy alkali PDTs for a high‐efficiency cell is also crucial for designing a high‐efficiency CIGS module. [ABSTRACT FROM AUTHOR]

This study focuses on boron‐doped p+polysilicon (poly‐Si) passivating contacts using spin‐on doping (SOD). Experimental conditions, including annealing conditions, SOD concentration, and poly‐Si thickness, were controlled to improve passivation. Based on the analysis results, the passivation quality mainly changes with indiffusion and doping concentration, causing Auger recombination and field effects. Meanwhile, grain size also influences the passivation quality but showed marginal characteristics. Through further optimization using an etch back and diffusion barrier, the efficiency of the flat reference solar cell was improved to 17.5% with an open‐circuit voltage of 695 mV using a p+ poly‐Si contact emitter, the highest reported efficiency using SOD on saw‐damage‐etched surfaces. This study includes a detailed analysis of SOD p+ poly‐Si and shows promising results with potential for application in tandem devices. Furthermore, the cell efficiency is expected to increase by controlling the doping profile and application of textured surfaces, selective emitters, and forming gas annealing (FGA). Highlights: The passivation quality of p + poly‐Si passivating contacts with boron SOD was investigated.The factors influencing the passivation quality of p+ poly‐Si were crystallinity (grain size), indiffusion of boron into the bulk, and doping concentration (field effect).The doping process was further optimized by controlling the boron indiffusion from the SOD source to c‐Si bulk using an additional diffusion barrier layer that controls the boron doping profile.Poly‐Si contact cells with both‐side flat surfaces and poly‐Si contacts showed a maximum efficiency of 17.5% with VOC of 695 mV when a developed p+ poly‐Si was applied at the front. This is the highest reported efficiency using boron SOD‐doped p+ poly‐Si emitter on saw‐damage‐etched flat surfaces.Based on a wide range of analyses and experimental results, a 3D energy band diagram of p+ poly‐Si/SiO x/c‐Si passivating contacts is exhibited.The cell result validates its potential for use in silicon‐based tandem solar cells and the efficiency can be further improved by applying textured surfaces, FGA, and selective emitter for improved metal contacts. [ABSTRACT FROM AUTHOR]

Synergistically enhancing luminescent and ferroelectric (SELF) properties are observed from a tetraphenylethene (TP) substituted with clipping groups (C), where the C is consisting of a 4‐[3,5‐bis‐(3‐decyloxy‐styryl)‐styryl]‐phenyl (DOS) unit. The DOS units of TPCn are self‐assembled via intermolecular interaction to clip themselves and induce TP aggregation, as evidenced by clip‐induced quenching of emission at DOS units (Eclip) accompanied by aggregation‐induced emission enhancement of TPs (EAIE). TPC4 demonstrates strong photoluminescence in a dilute chloroform solution and large EAIE in aqueous (>50%) THF solution. TPCn demonstrates SELF properties in film state, with high quantum yields of photoluminescence (>80%) and ferroelectric switching. Due to the introduction of four clips, TPC4 has a higher remnant polarization (Pr = 2.27 µC cm−2) at room temperature than TPC1. TPC4 is successfully employed in a light‐emitting electrochemical cell to achieve over 1290 cd m−2 under pulsed current conditions. The TPC4 film on a flexible substrate produced a piezoelectric output voltage of up to 0.13 V and a current density of 1.14 nA cm−2 upon bending. These results indicate that the side chain clipping and TP aggregation resulted in unprecedented flexible SELF properties in a single compound, offering simultaneous enhancement of electroluminescence, mechanical sensitivity, and energy harvesting capacity. [ABSTRACT FROM AUTHOR]

Local manipulation of the defect structures in 2D semiconducting transition metal dichalcogenide (2D TMD) opens rich research avenues harnessing their unique optoelectronic properties, where reliable defect structure formation methods are highly desirable. Here, the concept of optical soldering (OS) on few‐layer MoS2 to form site‐selective defect structures with induced photoluminescence (PL) is proposed and demonstrated. OS is initiated by optical heating of the top MoS2 layer to elevate the local temperature above the melting point of the underlying indium‐tin‐oxide nanoparticles (ITO‐NPs). In turn, thermally deformed ITO‐NPs pull the top MoS2 layer down to the substrate, forming the OS‐induced defect structure on the optically irradiated region. The OS‐induced defect structures on a few‐layer MoS2 show bright PL, which can be manipulated in peak positions by varying the incident optical power and irradiation time. OS is a facile method for local defect structure patterning on few‐layer MoS2 and manipulation of their optoelectronic properties while requiring low incidence optical power (≈2.5 mW) and fast process time (≈1 s), which are beneficial in the development of 2D TMD material‐based applications. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have emerged as the next generation of solar cells because of the promising nature of creating tandem solar cells with Si photovoltaics. Wide‐bandgap PSCs are developed to improve the power conversion efficiency (PCE) and stability of tandem devices. For the mass production of tandem solar cells, not only is a limitation of scalable coating a critical factor, but uncontrollable grain growth in ambient air impedes commercialization. Serious differences in morphology depending on the experimental environment are found. In the ambient air processing system, severe wrinkles and voids resulting in deteriorated photovoltaic performance are found as compared with those in N2 condition. It is suggested that humidity in the air plays a crucial role in the remaining perovskite intermediate phase and the rate of solvent evaporation during the spin‐coating procedure. Herein, void‐ and wrinkle‐free perovskite films using methyl ammonium chloride and formamide are fabricated, thus leading to efficient PSCs with a PCE of 20.6%. Furthermore, newly designed perovskite films to blade coating for large‐area fabrication as well as to semitransparent PSCs for a four‐terminal silicon/perovskite tandem solar cell with a PCE of 25.2% are applied. [ABSTRACT FROM AUTHOR]

The concept of microtissues has evolved to adapt to the generation of human tissue analogs that mimic physiologically relevant morphological and functional features. These microtissues can provide an in vitro testing platform for the development of advanced therapeutic options. Optimizing the manufacturing process of biomaterials brings several great benefits to achieve the desired mechanical, chemical, and biological properties for tissue modeling. Hence, 3D bioprinting technology has been utilized to fabricate functional microtissues. However, current microtissue bioprinting systems still require a cumbersome and time‐consuming task, such as washing, which renders it difficult to maintain the shape of intact constructs, thereby resulting in inappropriate tissue morphogenesis. To overcome this limitation, a single‐step bioprinting method is developed easier and more versatile for microtissue production based on a dual‐crosslinkable decellularized extracellular matrix with ruthenium/sodium persulfate (dERS). The developed method enables the fabrication of spheroidal and tubular microstructures into a medium chamber, followed by the immediate culturing of printed structures without multiple postprocesses. The structural characteristics can be controlled by adjusting the printing parameters. Each dERS‐based microtissue promotes tissue maturation and exhibits biofunctional attributes. These results suggest that the developed method may enable the simultaneous achievement of adequate print fidelity and tissue functionality. [ABSTRACT FROM AUTHOR]

Tandem solar cells which are electrically connected with various photoactive materials have the potential to solve the current challenges by exceeding the theoretically limited efficiency of single junction solar cells. Here the first monolithic organic/silicon tandem cell is reported based on a semitransparent polymer on a crystalline silicon (c‐Si) substrate. Herein, experimental results are presented for four‐terminal (4‐T) and monolithic two‐terminal (2‐T) organic/c‐Si tandem cells using organic cells with an inverted n‐i‐p structure and c‐Si cells with an n‐type TOPCon structure with detailed analysis. The best 4‐T tandem cell efficiency is 15.22%, and 2‐T results show that the top (organic) and bottom (c‐Si) cells are electrically connected by an open‐circuit voltage over 1.4 V. Further, a simulated efficiency of over 20% using the organic/c‐Si tandem is achieved, implying the tandem efficiency can be enhanced through further improvement of electric and optical characteristics with the optimization. [ABSTRACT FROM AUTHOR]

Aim: To develop a new general wards patient classification tool based on the nursing intensity level that reflects patients' clinical characteristics and indirect nursing activities. Design: A cross‐sectional design was adopted. This methodological study developed a patient classification system to sort general ward patients based on the intensity of their nursing needs and verified the validity and reliability of this classification system. Methods: Thirteen experts verified the tools' content validity. Data collectors and head nurses classified 150 patients from two hospitals with four general wards and various nurse staffing levels. Inter‐rater reliability was analysed. Staff nurses classified 846 patients following the Korean patient classification system on nursing intensity scores that reflected patients' clinical status. Content validity was verified based on the classification results. Using K‐group cluster analysis, score ranges for four groups were identified. Results: The developed tool includes 8 domains, (symptom management, infection control, nutrition and medication, personal hygiene and secretion, activity, sleep and rest, guidance in nursing/emotional support, nursing activity planning and coordination, indirect activity), 24 subdomains, 66 nursing activities and 124 criteria. Inter‐rater reliability showed high agreement. [ABSTRACT FROM AUTHOR]

We investigated field‐effect passivation by injecting negative charges into SiO2/SiNx stack using a plasma charge injection technique. The Si/SiO2/SiNx samples exhibited a very high flat‐band shift with a high injected negative charge density (>3.0 × 1013 cm2) after plasma negative charge injection; this density was higher than that for the well‐known Al2O3 layer. Most injected negative charges were present within approximately 90 nm of the surface of the SiNx layer deposited by plasma‐enhanced chemical vapor deposition (PECVD) when comparing the capacitance–voltage analysis results obtained while etching the SiNx film considering four assumptions of the injected negative charge distribution. The saturation current density in a 90‐ohm/sq boron emitter decreased from ~90 to 50 fA/cm2 after negative charge injection, which is equivalent to the J0e of the structure passivated with an Al2O3/SiNx stack. Six‐inch n‐type bifacial cells with an approximately 100‐ohm/sq boron emitter passivated with SiO2/SiNx displayed an approximately 0.2% increase in absolute cell efficiency after negative charge injection. In addition, n‐PERT bifacial cells with a high boron sheet resistance of ~150 ohm/sq exhibited a 1.0% or higher absolute efficiency enhancement from a relatively low precharging efficiency of approximately 19.0%. We also demonstrated that the final efficiency after charging was comparable with n‐PERT bifacial cells with Al2O3 passivation, suggesting that the proposed process is a potential low‐cost alternative method that could replace expensive Al2O3 processes. [ABSTRACT FROM AUTHOR]

Passivated contact structures are often representative of tunnel oxide passivated contact (TOPCon) and polycrystalline silicon on oxide (POLO) solar cells. These passivated contact technologies in silicon solar cells have experienced great strides in efficiency. However, characteristics analysis of poly‐Si/SiO2 applied to TOPCon and POLO solar cells as a carrier‐selective and passivated contact is still challenging because the silicon oxide film is very thin (<1.5 nm), poly‐Si and silicon oxide properties change during thermal treatment for passivation effects, and dopant diffusion from poly‐Si layer to the silicon wafer occurs. In this study, the interfacial analysis was performed by applying an algorithm based on the extended Shockley–Read–Hall (SRH) theory to the P‐doped poly‐Si/SiO2/c‐Si structure. Quantitative parameters of the P‐doped poly‐Si/SiO2/c‐Si interface were extracted by fitting the measured and simulated lifetime curves with algorithms, such as Dit (interface trap density) and Qf (fixed charge), from which we were able to elucidate the passivation effect of the interface. The interface analysis method using this algorithm is meaningful in that it can quantify the passivation characteristics of TOPCon with very thin silicon oxide film. The interface characteristics were also analyzed using the injection‐dependent lifetime after thermal treatment of P‐doped poly‐Si/SiO2/c‐Si samples for passivation effect. After the 850°C thermal treatment, the following best passivation effects were verified, namely, ψs = 0.248 eV, Dit = 1.0 × 1011 cm−2·eV−1, Qf = 2.4 × 1012 cm−2, and J02 = 370 pA·cm−2. Through the analysis model using carrier lifetime theory, we investigated quantitatively the passivation properties of P‐doped poly‐Si/SiO2/c‐Si. [ABSTRACT FROM AUTHOR]

Push–pull (D‐π‐A) dyes are explored for organic light‐emitting electrochemical cells (LECs) taking advantages of their tunability in the intramolecular charge transfer (CT) through a π‐bridge between donor and acceptor. These dyes present high thermal stability beyond 290 °C and fluorescence quantum yields (Φf), and simple thin film processability. The fluorene‐based dyes with diphenylamine donor (DPF) show high tunability in electroluminescence wavelength up to 825 nm that corresponds to the most red‐shifted metal‐free LECs reported to date. The DPFs show high irradiance under a low working voltage in the presence of poly(9‐vinylcarbazole) (PVK) and 2,5‐bis(5‐tert‐butyl‐benzoxazol‐2‐yl)thiophene (BBOT) hosts. As the CT distance of dyes is increased, Von of the LECs is decreased, since Φf and lifetime of dyes are higher. Furthermore, the smaller angle between the π‐bridge and acceptor (AπA) of dye is critical to increase irradiance, for a closer dye–host proximity. Thus a DPF dye with the lowest AπA (dye I) affords the highest irradiance of 425 µW cm−2 (>220 Cd m−2) among the dyes in this study. Therefore push–pull dyes could provide a rational material design principle toward near‐infrared emitting LECs. [ABSTRACT FROM AUTHOR]

Carbon nanotube electrode–laminated perovskite solar cells in combination with n‐type tunnel oxide–passivated contact silicon solar cells demonstrate a high power conversion efficiency (PCE) of 24.42% when stacked in tandem. This is compared with conventional indium tin oxide/MoOx‐deposited perovskite solar cells which give an efficiency of 22.35% when stacked in the same four‐terminal tandem system. Despite higher transmittance of the carbon nanotube electrode than that of the indium tin oxide/MoOx in the infrared range, the carbon nanotube electrode‐laminated devices show lower transmittance in the same region due to the total internal reflection and scattering as evidenced by optical simulation. Yet, the exceptionally high PCE of the carbon nanotube electrode‐laminated semitransparent devices far exceeding than that of the indium tin oxide/MoOx‐deposited semitransparent top cell outweighs the effect of the optical transparency. Four types of silicon solar cells are compared as the bottom subcells, and the n‐type tunnel oxide‐passivated contact silicon solar cells are the best choice mainly due to their high absorption in the long‐wavelength region. The obtained 24.42% efficiency is one of the high PCEs among the reported four‐terminal perovskite–silicon solar cells, and this article is the first demonstration of the carbon nanotube electrode application in tandem solar cells. [ABSTRACT FROM AUTHOR]

In the advent of next‐generation smart windows, materials play a multifunctional role, providing not only a pleasant environment for humans but also energy‐efficient buildings and transportation. To this ends, smart windows tend to integrate multiple functions with the purpose of controlling external or sunlight input, self‐power functionality, and display functionality. Among the several chromogenic mechanisms, electrochromic methods are fast and simple to control. Here, the recent electrochromic research on the integration of different functionalities is reviewed. Efforts toward the combination of functionalities have led to synergetic and technical breakthroughs over the years. These include development of new electrochromic polymers by main chain, as well as, side chain engineering, morphology and assembly control, and nanostructurization. In this context, electrochemical principles for smart windows offer easier integration of functionalities due to the integrative principles in common working mechanisms for color, energy, and information carrier controls. Some examples of multifunction devices are electrochromic capacitive windows, self‐powered smart windows, and electrochromic‐luminescent windows. Herein, discussed are the electrochromism from polymers and the electrochemically driven smart windows with two or more functionalities, which give rise to an innovative material with cooperative functions, featuring energy storage, energy generation, or light emission. [ABSTRACT FROM AUTHOR]

This study proposes a hybrid solar cell structure for a highly efficient silicon solar cell obtained by combining two passivating contact structures, namely, a heterojunction and polysilicon passivating contact. Given that the major cause of the loss in efficiency of crystalline silicon solar cells is carrier recombination at the metal‐semiconductor junction, a passivating contact having high‐quality passivation and a low contact resistance was introduced. In this study, two major passivating contact solar cells were combined. By applying an intrinsic thin amorphous silicon layer at the front and a tunneling oxide at the rear, a hybrid silicon solar cell with an efficiency of 21.8% was fabricated. Moreover, to evaluate the potential efficiency limit and to suggest methods for improving the cell performance of the proposed amorphous silicon emitter tunnel oxide back contact structure, the cell efficiency was simulated, and the result indicated that an efficiency of 26% could be achieved by controlling the thickness and resistivity of the wafer. [ABSTRACT FROM AUTHOR]

We report on novel pixel architecture for improving the transmittance and reducing the gamma distortion to minimize the color shift in an 8K QUHD LCD panel with the hG‐2D technology. In our LCD panel, each pixel has a unique electrode structure which is mixed with conventional micro‐slits and reversed those. It is named "multi‐domain reversed‐slit VA mode (MRS‐VA)". This MRSVA‐LCD has the excellent transmittance by matching the LC distortions on the vertical electrode and two data lines which is asymmetrically positioned. Besides, by shielding the LC distortion line at the oblique viewing angle, the gamma distortion can be effectively suppressed. Through our pixel structure, superior performances to conventional LCD could be clearly proved (GDI value: 0.345 and panel transmittance (T): 3.7%). Additionally, by demonstrations of overcoming the crosstalk and bruising defects, we demonstrated that MRSVA‐LCD could be applied to the commercial 8K panels manufactured by the mass production. [ABSTRACT FROM AUTHOR]

Purpose: Time of flight (TOF) PET reconstruction is well known to statistically improve the image quality compared to non‐TOF PET. Although TOF PET can improve the overall signal to noise ratio (SNR) of the image compared to non‐TOF PET, the SNR disparity between separate regions in the reconstructed image using TOF data becomes higher than that using non‐TOF data. Using the conventional ordered subset expectation maximization (OS‐EM) method, the SNR in the low activity regions becomes significantly lower than in the high activity regions due to the different photon statistics of TOF bins. A uniform recovery across different SNR regions is preferred if it can yield an overall good image quality within small number of iterations in practice. To allow more uniform recovery of regions, a spatially variant update is necessary for different SNR regions. Methods: This paper focuses on designing a spatially variant step size and proposes a TOF‐PET reconstruction method that uses a nonuniform separable quadratic surrogates (NUSQS) algorithm, providing a straightforward control of spatially variant step size. To control the noise, a spatially invariant quadratic regularization is incorporated, which by itself does not theoretically affect the recovery uniformity. The Nesterov's momentum method with ordered subsets (OS) is also used to accelerate the reconstruction speed. To evaluate the proposed method, an XCAT simulation phantom and clinical data from a pancreas cancer patient with full (ground truth) and 6× downsampled counts were used, where a Poisson thinning process was employed for downsampling. We selected tumor and cold regions of interest (ROIs) and compared the proposed method with the TOF‐based conventional OS‐EM and OS‐SQS algorithms with an early stopping criterion. Results: In computer simulation, without regularization, hot regions of OS‐EM and OS‐NUSQS converged similarly, but cold region of OS‐EM was noisier than OS‐NUSQS after 24 iterations. With regularization, although the overall speeds of OS‐EM and OS‐NUSQS were similar, recovery ratios of hot and cold regions reconstructed by the OS‐NUSQS were more uniform compared to those of the conventional OS‐SQS and OS‐EM. The OS‐NUSQS with Nesterov's momentum converged faster than others while preserving the uniform recovery. In the clinical example, we demonstrated that the OS‐NUSQS with Nesterov's momentum provides more uniform recovery ratios of hot and cold ROIs compared to the OS‐SQS and OS‐EM. Although the cost function of all methods is equivalent, the proposed method has higher structural similarity (SSIM) values of hot and cold regions compared to other methods after 24 iterations. Furthermore, our computing time using graphics processing unit was 80× shorter than the time using quad‐core CPUs. Conclusion: This paper proposes a TOF PET reconstruction method using the OS‐NUSQS with Nesterov's momentum for uniform recovery of different SNR regions. In particular, the spatially nonuniform step size in the proposed method provides uniform recovery ratios of different SNR regions, and the Nesterov's momentum further accelerates overall convergence while preserving uniform recovery. The computer simulation and clinical example demonstrate that the proposed method converges uniformly across ROIs. In addition, tumor contrast and SSIM of the proposed method were higher than those of the conventional OS‐EM and OS‐SQS in early iterations. [ABSTRACT FROM AUTHOR]

Abstract: 2D materials beyond molybdenum disulfide such as molybdenum ditelluride (MoTe2) have attracted increasing attention because of their distinctive properties, such as phase‐engineered, relatively narrow direct bandgap of 1.0–1.1 eV and superior carrier transport. However, a wafer‐scale synthesis process is required for achieving practical applications in next‐generation electronic devices using MoTe2 thin films. Herein, the direct growth of atomically thin 1T′, 1T′–2H mixed, and 2H phases MoTe2 films on a 4 in. SiO2/Si wafer with high spatial uniformity (≈96%) via metal–organic vapor phase deposition is reported. Furthermore, the wafer‐scale phase engineering of few‐layer MoTe2 film is investigated by controlling the H2 molar flow rate. While the use of a low H2 molar flow rate results in 1T′ and 1T′–2H mixed phase MoTe2 films, 2H phase MoTe2 films are obtained at a high H2 molar flow rate. Field‐effect transistors fabricated with the prepared 2H and 1T′ phases MoTe2 channels reveal p‐type semiconductor and semimetal properties, respectively. This work demonstrates the potential for reliable wafer‐scale production of 1T′ and 2H phases MoTe2 thin films employing the H2 molar flow rate‐controlled phase tunable method for practical applications in next‐generation electronic devices as a p‐type semiconductor and Wyle semimetal. [ABSTRACT FROM AUTHOR]

Gapless interdigitated back contact (IBC) solar cells were fabricated with phosphorous back surface field on a boron emitter, using an ion implantation process. Boron emitter (boron ion implantation) is counter doped by the phosphorus back surface field (BSF) (phosphorus ion implantation) without gap. The gapless process step between the emitter and BSF was compared to existing IBC solar cell with gaps between emitters and BSFs obtained using diffusion processes. We optimized the doping process in the phosphorous BSF and boron emitter region, and the implied Voc and contact resistance relationship of the phosphorous and boron implantation dose in the counter doped region was analyzed. We confirmed the shunt resistance of the gapless IBC solar cells and the possibility of shunt behavior in gapless IBC solar cells. The highly doped counter doped BSF led to a controlled junction breakdown at high reverse bias voltages of around 7.5 V. After the doping region was optimized with the counter doped BSF and emitter, a large-area (5 inch pseudo square) gapless IBC solar cell with a power conversion efficiency of 22.9% was made. [ABSTRACT FROM AUTHOR]

N-type silicon-based solar cells are currently being used for achieving high efficiency. However, most of the photovoltaic modules already constructed are based on p-type silicon solar cells, and there are few studies on potential induced degradation ( PID) in n-type solar cells. In this study, we investigated PID in n-type silicon solar cells with a front p+ emitter. Further, the PID characteristics of n-type solar cells are compared with those of p-type solar cells. The electrical properties of PID in solar cells are observed with the light I-V, quantum efficiency ( QE), and electroluminescence ( EL). The possible causes for the change in the external quantum efficiency ( EQE) after PID are interpreted using PC1D and are discussed by comparing the experimental results with the simulation results. [ABSTRACT FROM AUTHOR]

Scalable and economical manufacturing of flexible transparent conducting films (TCF) is a key barrier to widespread adoption of low-cost flexible electronics. Here, a simple, robust, and scalable method of flexible TCF formation using supersonic kinetic spraying is demonstrated. Silver nanowire (AgNW) suspensions are sprayed at supersonic speed to produce self-sintered films of AgNWs on flexible substrates. These films display remarkably low sheet resistance, <10 Ω sq−1, combined with high transmittance, >90%. These electrically conducting, transparent, and flexible coatings can be deposited over a 100 cm2 area in ≈30 s. Theoretical analysis reveals the underlying physical mechanism behind self-sintering, showing that self-sintering is enabled by the high velocity of impact in supersonic spraying. [ABSTRACT FROM AUTHOR]

Achieving high-specific-power and radiation hardness of solar cells is of great importance to perform tasks and achieve duration in space. Therefore, we investigated the proton irradiation resistance of ultralightweight CdS/CdTe thin film solar cells having high specific power values. High-energy proton beams (15 MeV) with doses ranging from 1×1012 to 1×1015 cm−2 were used, equivalent to more than 2000 years in low Earth orbit. Although 70 % decrease in cell conversion efficiency was observed after proton irradiation with dose of 1×1015 cm−2, it still maintained the photovoltaic performance. The specific power of the fabricated cell decreased from 358 W kg−1 to 109 W kg−1 after proton irradiation (dose=1×1015 cm−2), which is still comparable to specific powers of other types of solar cells. Our work indicated that reduction of short circuit current is a major factor of deterioration of the cell performance under the high energy proton irradiation. This work revealed that our lightweight CdS/CdTe solar cells have significant potential for the use in space applications: reduction of launch cost by achieving high specific power and assurance of durability over prolonged space missions. [ABSTRACT FROM AUTHOR]

Fire-through Ag thick-film metallization of crystalline Si ( c-Si) solar cells often yields macroscopically non-uniform contact quality over the cell area, degrading the cell performance and causing cell-to-cell variations of the conversion efficiency in a cell production line. This study analyzes the root cause of the 'gray finger' phenomenon, in which part of the fire-through Ag contact gridlines of a c-Si solar cell appears in gray or dark contrast in the electroluminescence images owing to high contact resistance. Few Ag crystallites were formed on the corrugated emitter surface at the contact interfaces underneath the gray fingers. The present results revealed that the gray finger phenomenon was caused by a short-circuit spot that formed between the Ag gridlines and underlying Si emitter during contact firing. The electrochemical reactions involved in fire-through Ag contact formation established a potential difference between the sintered Ag gridlines and Si emitter separated by molten glass. The molten glass acted as an electrolyte containing mobile Ag+ and O2− ions during contact firing. Therefore, the short-circuiting between the sintered Ag gridlines and Si emitter produced a galvanic cell during contact firing, which inhibited Ag crystallite formation at the contact interface along the gridlines in a short circuit and produced the gray fingers. The firing reactions in Ag thick-film contact formation could be interpreted in terms of the mixed potential theory of corrosion. The degradation of cell performance because of the gray finger phenomenon was also evaluated for 6-in. screen-printed c-Si solar cells. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study evaluated the impact of partial shading on CuInxGa(1-x)Se2 (CIGS) photovoltaic (PV) modules equipped with bypass diodes. When the CIGS PV modules were partially shaded, they were subjected to partial reverse bias, leading to the formation of hotspots and a possible occurrence of junction damage. In a module with a cadmium sulfide buffer layer, hotspots and wormlike defects were formed. The hotspots were formed as soon as the modules were shaded; the hotspots caused permanent damage (wormlike defects) in the CIGS module. Specifically, the wormlike defects were caused by the window layer, leading to increased recombination and decay of the solar cell properties. However, a CIGS module with a zinc sulfide buffer layer did not exhibit the formation of hotspots or any visual damage. The reverse bias breakdown voltage of the CIGS PV module with the cadmium sulfide buffer layer was higher than that of the CIGS PV module with the zinc sulfide buffer layer. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Boron-doped hydrogenated silicon carbide alloys containing silicon nanocrystallites (p-nc-SiC:H) were prepared using a plasmaenhanced chemical vapor deposition system with a mixture of CH4, SiH4, B2H6 and H2 gases. The influence of hydrogen dilution on the material properties of the p-nc-SiC:H films was investigated, and their roles as window layers in hydrogenated nanocrystalline silicon (nc-Si:H) solar cells were examined. By increasing the RH (H2/SiH4) ratio from 90 to 220, the SiC bond density in the p-nc-SiC:H films increased from 5.20 × 1019 to 7.07 × 1019/cm³, resulting in a significant increase of the bandgap from 2.09 to 2.23 eV in comparison with the bandgap of 1.95 eV for p-nc-Si:H films. For the films deposited at a high RH ratio, the Si nanocrystallites with a size of 3-15nm were formed in the amorphous SiC:H matrix. The Si nanocrystallites played an important role in the enhancement of vertical charge transport in the p-nc-SiC:H films, which was verified by conductive atomic force microscopy measurements.When the p-nc-SiC:H films deposited at RH = 220 were applied in the nc-Si:H solar cells, a high conversion efficiency of 8.26% (Voc=0.53V, Jsc = 23.98mA/cm² and FF = 0.65) was obtained compared to 6.36% (Voc=0.44V, Jsc = 21.90 mA/cm² and FF = 0.66) of the solar cells with reference p-nc-Si:H films. Further enhancement in the cell performance was achieved using p-nc-SiC:H bilayers consisting of highly doped upper layers and low-level doped bottom layers, which led to the increased conversion efficiency of 9.03%. [ABSTRACT FROM AUTHOR]

Al2O3 layers fabricated with atomic layer deposition (ALD) show high levels of surface passivation on p- and n-type silicon wafers. In order to form front and rear electrodes, Al2O3 layers should undergo a firing process at a high peak temperature. Therefore, the Al2O3 layer must be stable under these conditions to maintain a high level of surface passivation during the firing process. In this study, Al2O3 layers fabricated with ALD were pre-annealed to enhance their thermal stability during the firing process. From quasi-steady state photoconductance (QSSPC) measurements, the difference between the implied Voc values of the pre-annealed and fired samples was found to be smallest (3 mV) when the sample was pre-annealed at 620 °C. The surface recombination rate calculated from capacitance-voltage ( C- V) measurements of metal-Al2O3-Si (metal-insulator-semiconductor) structures was shown to be low when the sample was pre-annealed at 600-650 °C. Thus, firing stability was achieved with pre-annealing at 620 °C by reducing the surface recombination rate. We conclude that it is necessary to pre-anneal the Al2O3 passivation layer at this specific temperature to reduce the degradation of the passivation quality of Al2O3 after the firing process. [ABSTRACT FROM AUTHOR]

Vertically aligned long TiO2 nanotube (NT) electrodes with optimized structures for photovoltaic application were prepared by a two-step anodization method. The structures of the conventional TiO2 NT electrodes prepared by one-step anodization became severely bundled and disordered for tube lengths exceeding 20 μm. On the other hand, two-step anodization resulted in uniform and bundle-free TiO2 NT electrodes, with tube lengths of up to 38 μm. When used in dye-sensitized solar cells (DSSCs) as photoanodes, the two-step TiO2 NT electrodes exhibited enhanced short-circuit current density ( Jsc) with increasing tube length, owing to an increased roughness factor, which resulted in high dye loading. However, the dark current and open-circuit voltage decay (OCVD) curves confirmed that the electron recombination rate increased, and the electron lifetime decreased, with increasing tube length. This reduced electron lifetime resulted in sharp reductions in the open-circuit voltage ( Voc) with increasing tube length. Owing to the trade-off between the enhanced current density and the reduced electron lifetime, an optimal conversion efficiency of 4.56 % was obtained for a tube length of 29 μm. [ABSTRACT FROM AUTHOR]

Sol-gel derived nano-sized glass frits were incorporated into the Ag conductive ink for silicon solar cell metallization. This mixture was specifically formulated for inkjet printing on textured Si wafers with 80 nm thick SiN x anti reflection coating layers. The correlation between the contact resistance and interface microstructures were studied using scanning electron microscopy and transmission electron microscopy. In addition, the specific contact resistance between the front contact and emitter was measured at various firing conditions using the transfer length model. On an emitter with the sheet resistance of 60 Ω/sq, a specific contact resistance below 5 mΩ cm2 could be achieved at a peak firing temperature around 800 °C. We found that the incorporated nano-glass frit act as a very effective fire through agent, and an abundant amount of Ag crystallites was observed along the interface glass layer. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

ABSTRACT Back contacts for Si solar cells made by Al evaporation and screen printing Al paste were studied by transmission electron microscopy. Si was found to diffuse into the Al during heating. Si diffusion formed vacancies in the Si wafer and Al could then penetrate the Si wafer in spiked formations. The Al spikes retracted during cooling, leaving a doped back surface field region. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Photocatalytic and hydrophilic TiO2 thin-film applications include water purification, cancer therapy, solar energy conversion, self-cleaning devices, and antifogging windows. We demonstrate superhydrophilicity of aerosol-deposition ( AD) TiO2 films on a glass substrate without use of a carrier solvent, thereby removing the possibility of impurity contamination. AD films exhibit high visible light transmittance (greater than 80%) and superhydrophilicity (0° contact angle) with even minimal UV-light irradiation exposure. This AD method represents a significant step toward the realization of economically viable, functional thin films for the aforementioned applications. [ABSTRACT FROM AUTHOR]

A tunable surface that promotes either hydrophobic or hydrophilic behavior of TiO2 films is produced with aerosol deposition. This process is capable of mass production by high-speed coating at room temperature without any wet chemicals, and therefore the process has the potential to be economically viable, energy efficient, and environmentally friendly. Functional TiO2 films between 1 and 18 μm thick are produced by directly depositing dry, 1-μm TiO2 powders accelerated through a supersonic nozzle. Tunable film morphology due to a rough honeycomb surface structure yields variable water contact angles. When plasma treated with CF4, the films exhibit superhydrophilicity despite the rough honeycomb surface structure. Superhydrophilicity is due to the incorporation of fluorine in the film as shown using XPS. [ABSTRACT FROM AUTHOR]

Focuses on the change in concentration of sales among leading manufacturers in some relatively undifferentiated food processing industries in the United States in the 1980s. Result of the relaxation of of antitrust enforcement during the 1980s; Number of mergers that violated the Department of Justice Merger Guidelines of 1984.

Silicon Solar Cells: Multifunctional Effect of p-Doping, Antireflection, and Encapsulation by Polymeric Acid for High Efficiency and Stable Carbon Nanotube-Based Silicon Solar Cells (Adv. In article number 1902389, Il Jeon, Shigeo Maruyama, and co-workers demonstrate the multifunctional effects of Nafion polymer on carbon nanotube-based silicon solar cells. Antireflection, carbon nanotubes, doping, Nafion, silicon solar cells. [Extracted from the article]

Silicon solar cells among different types of solar energy harvesters have entered the commercial market owing to their high power conversion efficiency and stability. By replacing the electrode and the p‐type layer by a single layer of carbon nanotubes, the device can be further simplified. This greatly augments the attractiveness of silicon solar cells in the light of raw material shortages and the solar payback period, as well as lowering the fabrication costs. However, carbon nanotube‐based silicon solar cells still lack device efficiency and stability. These can be improved by chemical doping, antireflection coating, and encapsulation. In this work, the multifunctional effects of p‐doping, antireflection, and encapsulation are observed simultaneously, by applying a polymeric acid. This method increases the power conversion efficiency of single‐walled carbon nanotube‐based silicon solar cells from 9.5% to 14.4% and leads to unprecedented device stability of more than 120 d under severe conditions. In addition, the polymeric acid‐applied carbon nanotube‐based silicon solar cells show excellent chemical and mechanical robustness. The obtained stable efficiency stands the highest among the reported carbon nanotube‐based silicon solar cells. [ABSTRACT FROM AUTHOR]

Ultra‐lightweight CdTe thin film solar cells in space: The cover image depicts ultra‐lightweight thin‐film cadmium telluride (CdTe) solar cells as applied to the solar panels that power satellites. In the space environment, there are various radiation sources such as energetic particles and solar flares. Thus, solar cells that are robust to radiation are necessary for performing tasks in space successfully. Among various solar cell materials, CdTe thin films have the intrinsic radiation hardness suitable for aerospace applications. This work demonstrates robust and stable CdTe thin film solar cells on ultra‐thin glass substrates. The cell secured its high specific power even after severe proton irradiation. High radiation hardness makes these CdTe solar cells feasible for long‐term space missions. More details can be found in the Full Paper by G. Yang and E. Cho et al. from Korea University on page 1463 in Issue 11, 2016 (DOI: 10.1002/ente.201600346). [ABSTRACT FROM AUTHOR]

Al2O3 layers fabricated with atomic layer deposition (ALD) show high levels of surface passivation on p- and n-type silicon wafers. In order to form front and rear electrodes, Al2O3 layers should undergo a firing process at a high peak temperature. Therefore, the Al2O3 layer must be stable under these conditions to maintain a high level of surface passivation during the firing process. In this study, Al2O3 layers fabricated with ALD were pre-annealed to enhance their thermal stability during the firing process. From quasi-steady state photoconductance (QSSPC) measurements, the difference between the implied Voc values of the pre-annealed and fired samples was found to be smallest (3 mV) when the sample was pre-annealed at 620 °C. The surface recombination rate calculated from capacitance-voltage ( C- V) measurements of metal-Al2O3-Si (metal-insulator-semiconductor) structures was shown to be low when the sample was pre-annealed at 600-650 °C. Thus, firing stability was achieved with pre-annealing at 620 °C by reducing the surface recombination rate. We conclude that it is necessary to pre-anneal the Al2O3 passivation layer at this specific temperature to reduce the degradation of the passivation quality of Al2O3 after the firing process. [ABSTRACT FROM AUTHOR]