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Abstract: The temperature dependence of capacitance–voltage (C–V) and current voltage (I–V) characteristics were used to study the cause of high background doping and the underlying current transport mechanisms in GaAsN Schottky diode grown by chemical beam epitaxy (CBE). In one hand, a nitrogen-related sigmoid increase of junction capacitance and ionized acceptor concentration was observed in the temperature range 70–100K and was attributed to the thermal ionization of a nitrogen–hydrogen-related deep acceptor-state, with thermal activation energy of approximately 0.11eV above the valence band maximum (VBM) of GaAsN. This acceptor state is mainly responsible for the high background doping in unintentionally doped GaAsN grown by CBE. On the other hand, the I–V characteristics at different temperatures were found to deviate from the well known pure thermionic-emission mechanism. Based on their fitting at each temperature, the recombination current in the space charge region of GaAsN Schottky diode was mainly attributed to a hole trap, localized at 0.51eV above the VBM. Given the accuracy of measurements, this result was confirmed by deep level transient spectroscopy measurements. Nevertheless, considering the Shockley–Read–Hall model of generation-recombination, the recombination activity of this defect was quantified and qualified to be weak compared with the markedly degradation of minority carrier lifetime in GaAsN material. [Copyright &y& Elsevier]

Development of vehicles that are powered by photovoltaics (PV) is desirable, and is crucial for reduction in CO2 emissions from the transport sector to realize a decarbonized society. Our investigations show that the majority of the passenger cars that cruise only with solar energy can be realized by installing a high-efficiency PV module. Although the Toyota Prius demonstration car, which is equipped with a 860 W rated-output power PV module, has shown a 36.6 km dâˆ'1 PV-powered driving range at solar irradiance of 6.2 kWh mâˆ'2 dâˆ'1, practical driving ranges of PV-powered vehicles are shown to be shorter than the estimated values due to some losses of solar cell modules, such as temperature rise under sunny conditions. In this paper, we conduct a systematic analysis of the effects of these losses on the PV-powered driving range in order to obtain guidelines for the development of highly efficient solar cell modules for vehicle integrated applications. The analytical results show that the IIIâ€"V compound solar cell modules have more suitable properties compared to other cells because of their higher potential conversion efficiencies of 37% with a smaller temperature coefficient of âˆ'0.19% °Câˆ'1 compared to âˆ'0.29% °Câˆ'1 for Si back contact solar cell modules and âˆ'0.26% °Câˆ'1 for Si heterojunction solar cell modules. Our theoretical calculations that take these losses into account suggest that installing the IIIâ€"V-based triple-junction solar cell modules provides a potential PV-powered driving range of 30 km dâˆ'1 on average, and more than 50 km dâˆ'1 on a sunny day under the irradiation conditions in Japan. [ABSTRACT FROM AUTHOR]

We evaluated HfO2 films deposited by metal organic chemical vapor deposition using the Hf(N(C2H5)2)4/O2 gas system. The surface morphology and step coverage were simultaneously improved by increasing the deposition temperature. This improvement was achieved because the surface diffusion of reactants and/or their fragments was enhanced. At a low deposition temperature, N in Hf(N(C2H5)2)4 might disturb the surface diffusion of Hf, causing poor surface morphology and step coverage. [Copyright &y& Elsevier]

We investigated the degradation factor of the conversion efficiency of the silicon heterojunction solar cells. In particular, we clarified the effect of the transparent conductive oxide film deposition conditions on the film quality and interface states, and the relationship between these factors and the conversion efficiency. Heat process causes a decrease in carrier mobility due to a decrease in the grain size of the TCO film, but has an effect of improving the TCO/a-Si:H(p) interface states. In particular, the silicon oxide layer between the TCO film and a-Si:H(p) increases the series resistance and moderates the band bending at the TCO/a-Si:H(p) interface, leading to FF degradation. Since In 2 O 3 :H film easily forms a silicon oxide layer at the TCO/a-Si:H(p) interface, the interface treatment is important factor in the cell manufacturing process. [ABSTRACT FROM AUTHOR]

Potential-induced degradation (PID)-test results of modules fabricated from the rear- and front-emitter silicon heterojunction (SHJ) solar cells were compared to clarify the influence of the emitter position of SHJ photovoltaic (PV) cell modules on their PID behaviors. The PID tests were performed by applying a bias of −2000 V to the shorted interconnector ribbons from the front surface of the cover glass, at 85 °C. In the initial stage, both modules showed the same degradation characterized by a reduction in the short-circuit current density (J sc). After the first-stage degradation, the rear-emitter SHJ PV modules exhibited subsequent degradation characterized by a significant reduction in the J sc and open-circuit voltage (V oc), due to the enhancement of the minority-carrier recombination in the front surface region of the n-type crystalline silicon base. The front-emitter SHJ PV modules, on the other hand, showed a reduction in the fill factor (FF), in addition to moderate reductions in J sc and V oc. The FF reduction of the front-emitter SHJ PV modules is considered to be caused by the enhancement of the recombination in the front surface region of the n-type crystalline-silicon base as the region corresponds to the pn junction interface of the front-emitter configuration. The moderate reductions in both J sc and V oc may be due to further progression of the first-stage degradation. These findings are essential for understanding the mechanism of PID in SHJ PV cell modules. • Potential-induced degradation behaviors were compared of rear- and front-emitter silicon heterojunction PV modules. • Both modules showed the first-stage degradation with the same behavior characterized by a J sc reduction. • The rear-emitter modules showed the second-stage degradation characterized by significant reductions in J sc and V oc. • The front-emitter ones, on the other hand, showed degradation in FF together with moderate reductions in J sc and V oc. [ABSTRACT FROM AUTHOR]

A reactive-plasma deposition (RPD) process damage is evaluated for an indium-tin-oxide (ITO)/SiO2/Si structure in terms of the recombination properties at the interface. To calculate the surface recombination velocity (SRV), the defect density at the SiO2/Si interface (Dit), the effective total charge (Qtot) which is the sum of the charges in the SiO2 and the trapped charge at the SiO2/Si interface, and the workfunction of ITO at the ITO/SiO2 interface (ϕITO), are extracted by capacitance-voltage (C-V) analysis as a function of a postdeposition annealing (PDA) temperature. The Dit and Qtot significantly increase by the RPD process to 1.4×1012 cm-2eV-1 and 1.5×1012/q cm-2, respectively, and decrease by the PDA at 200 °C in N2 ambient to 1.4×1011 cm-2eV-1 and 1.1×1011/q cm-2, respectively. The ϕITO also varies from 4.80 eV to 4.35 eV by the PDA. The correlation is examined between the SRV values calculated based on the extended SRH model using the extracted Dit, Qtot, and ϕITO values [SRV(CV)], and the SRV ones obtained from the minority carrier lifetime measurements [SRV(LT)]. It is found that multiple sets of capture cross-sections were required for SRV(CV) values to coincide with SRV(LT) ones. The effect of variation in the Qtot and ϕITO on the band bending is almost canceled out in the present PDA condition. It is thus considered that the increase in Dit is the main cause to decrease the minority carrier lifetime. [ABSTRACT FROM AUTHOR]

Dislocation-mediated strain relaxation during lattice-mismatched InGaAs/GaAs(001) heteroepitaxy was studied through in situ x-ray reciprocal space mapping (in situ RSM). At the synchrotron radiation facility SPring-8, a hybrid system of molecular beam epitaxy and x-ray diffractometry with a two-dimensional detector enabled us to perform in situ RSM at high-speed and high-resolution. Using this experimental setup, four results in terms of film properties were simultaneously extracted as functions of film thickness. These were the lattice constants, the diffraction broadenings along in-plane and out-of-plane directions, and the diffuse scattering. Based on correlations among these results, the strain relaxation processes were classified into four thickness ranges with different dislocation behavior. In addition, the existence of transition regimes between the thickness ranges was identified. Finally, the dominant dislocation behavior corresponding to each of the four thickness ranges and transition regimes was noted. [ABSTRACT FROM AUTHOR]

• PID tests for crystalline Si photovoltaic modules without front cover glass and using cells with various electrode pastes of controlled additive contents were performed. • This phenomenon is similar to that induced by Na in the front cover glass, but, it requires the shorter time duration as compared with the case of Na in the front cover glass. • In addition, it is found that Li in the paste also causes the PID equivalent to that by Na in the paste. Sodium (Na) and lithium (Li) in the silver (Ag) paste cause the potential-induced degradation (PID), while the PID of p-type crystalline silicon (Si) photovoltaic modules is caused by Na in the front cover glass. Some Ag pastes contain these elements to control the firing properties in solar cells fabrication. In order to eliminate the effect of Na and other elements in the front cover glass on PID, PID tests for crystalline Si photovoltaic modules without front cover glass and using cells with various electrode pastes of controlled additive contents were performed. When the Ag paste with Na is used, the shunt resistance decreases and the PID occurs. This phenomenon is similar to that induced by Na in the front cover glass, but, it requires the shorter time duration as compared with the case of Na in the front cover glass. In addition, it is found that Li in the paste also causes the PID equivalent to that by Na in the paste. [ABSTRACT FROM AUTHOR]

Abstract We have investigated the effects of chemical rounding (CR) on the surface passivation and/or antireflection performance of AlO x - and AlO x /SiN x :H stack-passivated pyramid textured p +-emitters with two different boron doping concentrations, and on the performance of bifacial n -PERT Si solar cells with a front pyramid textured p +-emitter. From experimental results, we found that chemical rounding markedly enhances the passivation performance of AlO x layers on pyramid textured p +-emitters, and the level of performance enhancement strongly depends on boron doping concentration. Meanwhile, chemical rounding increases solar-weighted reflectance (R SW) from ∼2.5 to ∼3.7% for the AlO x /SiN x :H stack-passivated pyramid textured p +-emitters after 200-sec chemical rounding. Consequently, compared to non-rounded bifacial n -PERT Si cells, the short circuit current density J sc of 200- sec -rounded bifacial n -PERT Si cells with ∼60 and ∼100 Ω/sq p +-emitters is reduced by 0.8 and 0.6 mA/cm2, respectively under front p +-emitter side illumination. However, the loss in the short circuit current density J sc is fully offset by the increased fill factor FF by 0.8 and 1.5% for the 200- sec -rounded cells with ∼60 and ∼100 Ω/sq p +-emitters, respectively. In particular, the cell efficiency of the 200- sec -rounded cells with a ∼100 Ω/sq p +-emitter is enhanced as a result, compared to that of the non-rounded cells. Based on our results, it could be expected that the cell efficiency of bifacial n -PERT Si cells would be improved without additional complicated and costly processes if chemical rounding and boron doping processes can be properly optimized. Highlights • Chemical rounding is studied to enhance performance of pyramid textured p +-emitters. • Chemical rounding largely reduces surface recombination of textured p +-emitters. • Chemical rounding, however, increases reflectance of textured p +-emitters also. • Bifacial n -PERT cells are subjected to J SC loss due to the increased reflectance. • J SC loss is offset by enhanced FF through optimization of rounding and boron doping. [ABSTRACT FROM AUTHOR]

The frequency dependent capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics of Schottky barrier diodes (SBDs) with Cu contacts on Si doped GaAsN epilayers with (100) and (311)A/B orientations have been investigated in the frequency range from 20 kHz to 1 MHz at room temperature. C, G/ω and the deduced series resistance (R s ) show strong dependences on the applied frequency in the forward bias region, which is closely correlated to the frequency-dependent response of interface states (N ss ). In GaAsN SBDs with all three growth orientations, the increasing N composition is found to increase the peak value of capacitance and enhance its dependence on frequency, which thus implies a general rule that increasing N incorporation causes an increase in N ss . The increasing extent of N ss due to N incorporation, however, differs a lot for different growth orientations as analyzed by using Hill-Coleman method. It is revealed that (311)B is the promising growth orientation to suppress the N ss generation over a wider N composition range in GaAsN Schottky devices. The reduced formation probability of non-substitutional N due to the efficient N incorporation on the (311)B plane is considered to be responsible for the observations. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new method of using H 2 supply in the atmosphere to increase Sn concentration in a Ge 1−x Sn x film epitaxially grown on a Ge substrate using MOCVD (metal organic chemical vapor deposition). H 2 supplied in the atmosphere accelerates decomposition of Sn precursors and suppresses surface migration of Sn atoms during epitaxial growth of a Ge 1−x Sn x film. The proposed method is new and fundamentally different from the existing methods that increase Sn concentration through either crystallizing α-Ge 1−x Sn x or lowering growth temperature. The proposed method uses H 2 supply in the atmosphere to increase Sn concentration. In order to show the effectiveness of the proposed method, we conducted experiments with varying ratios of supplying H 2 in the atmosphere and epitaxially grew a Ge 1−x Sn x film on a Ge substrate using MOCVD. MO precursors that we used in our experiments (tertiarybutylgermane and tetraethyl tin) are new and safe. In our experiments, we observed that Sn concentration increased with H 2 supply during growth, while maintaining a high growth rate of a Ge 1−x Sn x film. [ABSTRACT FROM AUTHOR]

The N–H related defects at 3124 cm -1 are found to be acceptors in GaAsN grown by chemical beam epitaxy (CBE), by comparing the concentrations of N–H defects with those of acceptors as a function of annealing condition. The vibrations of N–H defects appear as local vibration modes at 2952, 3011, 3098, and 3124 cm -1 using Fourier transform infrared (FTIR) spectroscopy. The integrated absorptions at 2952 and 3098 cm -1 decrease, at 3011 cm -1 remain small, while at 3124 cm -1 increases due to the annealing treatment. On the other hand, the concentration of acceptors increases with the annealing time, based on capacitance–temperature (C–T) measurement. The densities of N–H defects at 3124 cm -1 and those of acceptors are almost equal independent of the annealing condition. This result suggests that the N–H defects appearing at 3124 cm -1 play the role of acceptors in GaAsN grown through CBE. [ABSTRACT FROM AUTHOR]

[Display omitted] • Demonstration of passivation of InAs surface quantum dots by atomic layer deposition. • Surface native oxide removal during passivation capping. • Diethlzinc/ZnO self-clean-up enhanced photoluminescence. • Suppressed photoluminescence peak blueshift after capping. • Preservation of surface quantum dot size and shape after capping. Passivation capping of molecular beam epitaxy (MBE)-grown InAs surface quantum dots (SQDs) is achieved by ex situ atomic layer deposition (ALD)-grown ZnO using diethylzinc (DEZ) as the zinc precursor, the main passivation agent, and oxygen plasma. Photoluminescence (PL) intensity is enhanced by 2-fold as the DEZ/ZnO passivation cap thickness reached 30 nm. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) show that contrary to conventional wet chemistry passivation or MBE capping, in which InAs SQDs can be damaged or be shrunken by intermixing of In and Ga, DEZ/ZnO passivation capping almost preserves the shape of the underlying SQDs. The cross-sectional analysis with transmission electron microscopy (TEM) reveals the formation of the ZnO grains on top of the sample accompanied by slight SQD height and width reduction, which are presumably related to the removal of the InAs native oxides. The DEZ "self-clean-up" passivation mechanism, where zinc precursor is responsible for reduction of the surface non-radiative recombination sites, is studied by X-ray photoelectron spectroscopy (XPS). The factors that control the DEZ "self-clean-up" efficiency such as the chain of chemical reactions, steric hindrance, decomposition activation energy, Gibbs reactivity, or Lewis acidity, are evaluated. The results are discussed in comparison with trimethylaluminum (TMA), a precursor used for Al 2 O 3 deposition. We find that the "self-cleaning" by DEZ and TMA occurs through processes of different chemical nature. [ABSTRACT FROM AUTHOR]

The growth orientation dependence of N incorporation on traditional (100) and high-index GaAs (311)A/B planes has been investigated by the first principle calculation and experimental measurement. Due to the electronegativity and atomic radius differences between As and N atoms, the Ga N bond is much shorter than the corresponding Ga As bond as N occupies As atom site. The optimization to energetically preferred construction leads to the inward moving of N atom, while the displacement extent of three surface models exhibits considerable differences. More importantly, the theoretical result reveals a lower formation energy of N doping for N@(311)B GaAs surface and a larger one for N@(311)A GaAs surface as compared with the traditional (100) GaAs plane. The first principle investigations thus suggest the enhanced N incorporation in (311)B GaAsN, which is in good accordance with the secondary ion mass spectrometry (SIMS) measurement results of GaAsN layers by chemical beam epitaxy (CBE). [ABSTRACT FROM AUTHOR]

The contact behavior of Cu on n-type GaAsN, grown on (100) and (311)A/B GaAs substrates by chemical beam epitaxy, has been investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements. Both N incorporation and growth orientation are found to influence the electrical properties of Cu/GaAsN Schottky diodes. The increasing N composition leads to an increase in the ideality factor and Schottky barrier height (C–V), whereas a decrease in the carrier concentration in samples with all adopted growth orientations. Compared with (100) and (311)B samples, the Schottky diodes constructed on (311)A GaAsN epilayer exhibit better performance with ideality factor close to 1 and higher barrier height. The interfacial chemical reaction between metal layer and surface atoms on the growth surface is believed to account for the observations. [ABSTRACT FROM AUTHOR]

The N–H related acceptor defects in GaAsN grown by chemical beam epitaxy (CBE) are studied by hydrogen isotopes, H and D. When the films are grown by a conventional arsenic source, deep level transient spectroscopy (DLTS) reveals two energy levels at 0.11 and 0.19 eV above the valence band. These levels were considered to act as a double acceptor in the literature. When the films are grown by a deuterated arsenic source, new signals appear in DLTS spectra at 0.15 and 0.23 eV. This indicates that the new signals are originated from D-related defects. The energy differences between 0.15 and 0.11 eV, and that between 0.23 and 0.19 eV are same (0.04 eV). Although these energy levels become deeper with increasing the growth temperature, the energy differences are almost constant independent of the growth condition. In addition, the intensity ratios of the peaks at 0.15 (0.23) eV to that at 0.11 (0.19) eV have a good correlation with the isotopic concentration ratio of D to H in the grown films. Therefore, we conclude that the energy differences and intensity ratios of the DLTS peaks occur due to the structural change from N–H to N−D in the same type of defect, and that this acceptor is an N–H related defect. [ABSTRACT FROM AUTHOR]

Abstract: Growth temperature dependence of strain relaxation during In0.12Ga0.88As/GaAs(001) molecular beam epitaxy was studied by in situ X-ray reciprocal space mapping. Evolution of the residual strain and crystal quality for the InGaAs film was obtained as a function of film thickness at growth temperatures of 420, 445 and 477°C. In the early stages of strain relaxation, it was found that evolution of the residual strain and crystal quality was dependent on the growth temperature. In order to discuss this observation quantitatively, the strain relaxation model was proposed based on the Dodson–Tsao kinetic model, and its validity was demonstrated by good agreement with the experimental residual strain. Additionally, rate coefficients reflecting dislocation motions during strain relaxation were obtained as a function of growth temperature and strain relaxation was discussed in terms of the thermally active dislocation motion. [Copyright &y& Elsevier]

The current research focuses on the Intracellular biosynthesis of Ag/AgCl nanohybrids in microalgae, Scenedesmus sp. The effect of biosynthesis process on growth and lipid profile of cells is key element of this study. Ag/AgCl nanohybrids synthesized intracellularly were characterized by UV–Vis spectrophotometer, Powder X-Ray Diffraction (P-XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM). 10–20 nm and 10–50 nm sized spherical shaped nanoparticles of polycrystalline nature were grown using 0.5 and 1 mM of AgNO 3 precursor, respectively and Scenedesmus sp. as reducing agent. Total lipid content of the cells treated with 0.5 mM and 1 mM AgNO 3 was static and found to be 43.2 ± 0.01 μg/mL and 48.2 ± 0.02 μg/mL respectively at 120 h of Ag/AgCl nanoparticles biosynthesis. FAME (Fatty Acid Methyl Ester) profile was improved due to intracellular nanoparticles biosynthesis with maximum C16:0 (palmitic acid) (35.7%) in cells treated with 0.5 mM AgNO 3 used for Ag/AgCl nanohybrids synthesis. Palmitic acid in cells exposed to 0.5 mM concentration of metallic precursor increased by 75.86%. Synthesized nanoparticles were tested on four bacterial strains to establish its antibacterial efficiency showing appropriate zone of inhibition at varying concentrations. Present study efficiently demonstrates the utility of microalgae integrating nanoparticles biosynthesis and lipid accumulation. [Display omitted] • 10–20 nm size silver nanoparticles were biosynthesized intracellularly in Scenedesmus sp. • X-ray diffraction and electron microscopy were used to characterize silver nanoparticles. • 75.86% increase in saturated fatty acid was observed during NPs synthesis. • Synthesized nanoparticles showed antibacterial properties against four bacterial strains. [ABSTRACT FROM AUTHOR]

• Atomic layer deposition of Ta-doped TiO 2 thin films for electron-selective contacts. • Dramatical improvement of passivation quality of the TiO 2 films by moderate Ta doping. • Effective minority-carrier lifetime increased by about 40% by 1.5 at.% Ta doping. • However, overdoping rather degrades the passivation quality of TiO 2 thin films. We demonstrate that the passivation quality of TiO 2 electron-selective contacts can be improved by Ta doping. By using atomic layer deposition, 3.5-nm-thick, undoped TiO 2 films and Ta-doped TiO 2 (TiO 2 :Ta) films with Ta concentrations of 1.5, 2.8, and 5.5 at.% were formed on n-type crystalline silicon substrates with chemical SiO 2 layers. After annealing at 130 °C, the effective minority-carrier lifetime (τ eff) of the TiO 2 :Ta-passivated samples were significantly higher than that of the undoped-TiO 2 -passivated samples, and the highest τ eff was obtained at a relatively low Ta-doping concentration of 1.5 at.%. These indicate that moderate Ta doping improves the passivation quality of TiO 2 thin films. [ABSTRACT FROM AUTHOR]

Abstract: The minority carrier diffusion length in Chemical Beam Epitaxy (CBE) grown GaAs0.995N0.005 based homo-junction solar cell was estimated and found to be L =0.08μm. In addition, the majority carrier traps in N-varying unintentionally doped p-type GaAsN samples grown by CBE were investigated using Deep Level Transient Spectroscopy (DLTS) technique. Five hole traps, HC1–HC5, were detected, where HC2 and HC5 coexist in all samples. These two hole traps were suggested to be a N-related defect and the double donor state of EL2, respectively. [Copyright &y& Elsevier]

Recent trends in two-dimensional (2D) graphene have demonstrated significant potential for gas-sensing applications with significantly enhanced sensitivity even at room temperature. Herein, this study presents fabrication of distinctive gas sensor based on one-dimensional (1D) W 18 O 49 nanofibers decorated 2D graphene, specifically coated on copper (Cu)-based interdigitated electrodes formed by DC sputtering, which can selectively detect NO 2 gas at room temperature. The sensor device fabricated using W 18 O 49 /Gr1.5% (i.e., W 18 O 49 nanofibers hybrid nanocomposite with 1.5 wt % graphene) displays excellent overall sensing performance at 27 °C (room temperature) with high response (∼150-160 times) to NO 2 gas. The W 18 O 49 /Gr1.5%-based sensor device reflects the highly selective detection toward NO 2 gas among various gases with quick response time of 3 s and speedy recovery in 6 s. The limit of detection of ∼0.3 ppm with excellent reproducibility and stability for 3 months in all weather conditions (tested in humidity conditions 20-97%) are superior features of the device under test. However, W 18 O 49 /Gr3% displayed higher selectivity for NO 2 but resulted with comparatively reduced sensitivity than W 18 O 49 /Gr1.5% sensor. The enhanced sensing performance could be attributed to the graphene content to decorate the nanofibers on it, oxygen vacancies/defects, and the contacts between the sensing material and Cu. This favorable synthesis and properties of self-assembled hybrid composite materials provide a potential utilization for detecting NO 2 gas in environmental safety inspection.

For SiO 2 layers underneath the SiN x antireflection/passivation layers of front-emitter p-type c-Si solar cells, this paper presents an investigation into their effects on polarization-type potential-induced degradation (PID), in addition to a comparison of polarization-type PID behavior in front-emitter p-type c-Si cells and front-emitter n-type c-Si cells. After PID tests with a bias of +1000 V, p-type c-Si cells without SiO 2 layers underneath the SiN x layers showed no degradation, although p-type c-Si cells with approx. 10 nm thick SiO 2 layers showed polarization-type PID, which is characterized by a reduction of the short-circuit current density and the open-circuit voltage. This result implies that highly insulating layers such as SiO 2 layers play an important role in the occurrence of polarization-type PID. Comparison of polarization-type PID in p-type and n-type c-Si cells with SiO 2 layers indicated that degradation in the n-type cells is greater and saturates in a shorter time than in the p-type cells. This result is consistent with an earlier proposed model based on the assumption that polarization-type PID is caused by charge accumulation at K centers in SiN x layers. The findings described herein are crucially important for elucidating polarization-type PID and verifying the degradation model., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Defects such as oxygen vacancy in the nanostructures have paramount importance in tuning the optical and electronic properties of a metal oxide. Here we report the growth of oxygen deficit tungsten oxide (W 18 O 49 ) nanorods modified with ruthenium oxide (RuO 2 ) using a simple and economical hydrothermal approach for energy storage application. In this work, a novel approach of hybridizing the W 18 O 49 nanostructure with RuO 2 to control the electrochemical performance for energy storage applications has been proposed. The result displays that the hybridization of the nanostructures plays an important role in yielding high specific capacitance of the electrode material. Due to the augmentation of W 18 O 49 and RuO 2 nanostructures, the galvanostatic charging and discharging (GCD) mechanism exhibited the transformation from the battery type characteristics of W 18 O 49 into the typical pseudocapacitor feature of hybrid architect nanostructure due to defect creations. The electrochemical measurement of hybrid nanomaterial shows the doubling of specific capacitance to 1126 F/g and 1050 F/g in cyclic voltammetry (CV) and GCD, respectively, in comparison with W 18 O 49 and RuO 2 and earlier reports. The enhancement in the stability performance up to 3000 cycles of hybrid is indebted to the stable nature of W 18 O 49 and the high conductivity of RuO 2 .

In this work, we have successfully proclaimed the importance of defect prone nanostructure on to the electrode surface for the promising glucose sensing applications. Oxygen-deficient W 18 O 49 moieties with multiple valences W 6+ and W 5+ have been investigated as an efficient electrocatalyst for the nonenzymatic glucose sensing. In order to highlight the importance of the defect, WO 3 nanomaterial's electrode has also been synthesized and tested for glucose sensing. W 18 O 49 delivers a larger Brunauer-Emmett-Teller (BET) surface area and mesoporous pores which have contributed to the high sensitivity performances. The oxygen vacant W 18 O 49 nanostructure has been synthesized by a facile solvothermal route and has retained interconnected nanorods morphology. Compared with non-oxygen-deficient WO 3 , this defect prone version of tungsten oxide (W 18 O 49 ) possesses a doubled linearity range up to 1.6 mM maximum electrooxidation toward glucose by giving a 1.6 times higher sensitivity of 167 μA mM -1 cm -2 , 0.5 times lower detection limit of 0.02 μM ( S / N = 3), and a swift response time of 5 s.

We have used transient electron-beam-induced current (EBIC) to map minority carrier lifetime distributions in multicrystalline Silicon (mc-Si). In this technique, the electron beam from a scanning transmission electron microscope was on-off modulated while the sample was scanned. The resulting transient EBIC was analyzed to form a lifetime map. An analytical function was introduced as part of the analysis in determining this map. We have verified this approach using numerical simulations and have reproduced a lifetime map for an mc-Si wafer.