Institute of Ion Plasma Laser Technologies

Abstract Although perovskite solar cells (PSCs) are on the road to industrialization, the operational stability under high efficiency still needs to be improved, and the water solubility of lead ions (Pb 2+ ) will cause environmental pollution problems. Herein, it is successfully implanted an environment‐friendly (biodegradability) poly(butylene adipate‐coterephthalate) polymer (PBAT) into the perovskite film, which can passivate the uncoordinated Pb 2+ and neutral iodine defects of the perovskite material because of the adequate carbonyl groups and benzene rings in PBAT polymer, thereby regulating the crystallization of perovskite film with lower trap density, inhibiting the nonradiative recombination and improving charge carrier transport. As a result, the polymer‐incorporated inverted PSCs achieve optimal conversion efficiencies of 22.07% (0.1 cm 2 ) and 20.31% (1 cm 2 ). Meanwhile, the incorporated device, after being encapsulated, exhibits a prominent improvement in operational stability of high‐efficiency device under maximum power point tracking and continuous one sunlight illumination, maintaining the initial efficiency of 80% for 3249 h. More importantly, the polymer network can protect Pb 2+ from being dissolved by water and prevent nearly 98% of Pb 2+ from leaking by directly immersing the polymer‐coated perovskite film in water. Environmental‐friendly molecules provide new hope for solving lead poisoning and improving device operational stability under high efficiency.

We optimize force fields for H3O(+) and OH(-) that reproduce the experimental solvation free energies and the activities of H3O(+) Cl(-) and Na(+) OH(-) solutions up to concentrations of 1.5 mol/l. The force fields are optimized with respect to the partial charge on the hydrogen atoms and the Lennard-Jones parameters of the oxygen atoms. Remarkably, the partial charge on the hydrogen atom of the optimized H3O(+) force field is 0.8 ± 0.1|e|--significantly higher than the value typically used for nonpolarizable water models and H3O(+) force fields. In contrast, the optimal partial charge on the hydrogen atom of OH(-) turns out to be zero. Standard combination rules can be used for H3O(+) Cl(-) solutions, while for Na(+) OH(-) solutions, we need to significantly increase the effective anion-cation Lennard-Jones radius. While highlighting the importance of intramolecular electrostatics, our results show that it is possible to generate thermodynamically consistent force fields without using atomic polarizability.

Among all‐inorganic perovskite photoactive materials, CsPbIBr 2 demonstrates the most balanced trade‐off between optical bandgap and phase stability. However, the poor quality and high‐temperature engineering of CsPbIBr 2 film hinder the further optimization of derived perovskite solar cells (PSCs). Herein, a simple dynamic vacuum‐assisted low‐temperature engineering (merely 140 °C) is proposed to prepare high‐quality CsPbIBr 2 film (VALT‐CsPbIBr 2 film). Compared to HT‐CsPbIBr 2 film processed via conventionally high temperature (280 °C), VALT‐CsPbIBr 2 film presents higher crystallinity and more full coverage consisting of larger grains and fewer grain boundaries, which results in intensified light‐harvesting capability, reduced defects, and extended charge carrier lifetime. Benefiting from those improved merits, VALT‐CsPbIBr 2 PSCs show lower trap‐state densities, more proficient charge dynamics, and larger built‐in potential than HT‐CsPbIBr 2 PSCs. Consequently, VALT‐CsPbIBr 2 PSCs deliver a higher efficiency of 11.01% accompanied by a large open‐circuit voltage of 1.289 V and a remarkable fill factor of 75.31%, being highly impressive among those reported CsPbIBr 2 PSCs. By contrast, the efficiency of HT‐CsPbIBr 2 PSCs is only 9.00%. Moreover, VALT‐CsPbIBr 2 PSCs present stronger endurance against heat and moisture than HT‐CsPbIBr 2 PSCs. Herein, a feasible avenue to fabricate efficient yet stable all‐inorganic PSCs via low‐temperature engineering is provided.

Abstract Anode‐free sodium batteries (AFSBs) hold great promise for high‐density energy storage. However, high‐voltage AFSBs, especially those can stably cycle at a wide temperature range are challenging due to the poor electrolyte compatibility toward both the cathode and anode. Herein, high‐voltage AFSBs with cycling ability in a wide temperature range (−20–60 °C) are realized for the first time via a sole‐solvent high‐entropy electrolyte based on the diethylene glycol dibutyl ether solvent (D2) and NaPF 6 salt. The sole‐solvent high‐entropy electrolyte with unique solvent‐ions effect of strong anion interaction and weak cation solvation enables entropy‐driven electrolyte salt disassociation and high‐concentration contact ion pairs, thus simultaneously forming stable anion‐derived electrode–electrolyte interphases on cathode and anode. Moreover, the wide liquid range of D2 further extends the temperature extremes of the battery. Consequently, ampere‐hour (Ah)‐level anode‐free sodium pouch cells with cyclability in a wide temperature range of −20–60 °C are realized. Impressively, the pouch cell achieves a leadingly high cell‐level energy density of 209 Wh kg −1 and a high capacity retention of 83.1% after 100 cycles at 25 °C. This work provides inspirations for designing advanced electrolytes for practical AFSBs.

Approximating the C60 shell as a collection of carbon atoms, the potential experienced by a confined atom has been calculated within the framework of the self-consistent spherical jellium model. It has been found that the potential well in this model has a cusp-shaped Lorentz-like profile. The parameters of the model Lorentz-bubble potential (depth and thickness) have been selected so that in the potential well there would be an electronic level corresponding to the experimental electron affinity of the C60 molecule. The spatial distribution of the positive charge of the C-atomic nuclei and the negative charge of the electron clouds forming the electrostatic potential of C60, as a whole, has been analyzed using the Poisson equation. It is demonstrated that the often used radial square-well potential to approximate the C60 corresponds to a non-physical charge density for the C60 molecule. This analysis demonstrates that the phenomenological potentials simulating the C60 shell potential should belong to a family of potentials with a non-flat bottom and non-parallel potential walls similar to the Lorentz-bubble potential. The photoionization cross-sections of a hydrogen atom localized at the center of the C60 shell have been calculated as well. It is found that confinement oscillations in the cross-sections are exhibited within the framework of the cusp-shaped potential model and these oscillations are essentially the same as those in the case of the potential wells with well-defined borders (parallel walls), thereby demonstrating that the inherent characteristic distances of the potential, e.g., radii of the potential walls, or the distances between potential walls, are not necessary to produce confinement resonances; this should be a general result for atoms or molecules confined in near-spherical fullerenes.

In this paper, the important issue of the desorption of less- and nonvolatile compounds with minimal sample decomposition in ambient mass spectrometry is approached using ambient flash desorption mass spectrometry. The preheated stainless steel filament was driven down and up along the vertical axis in 0.3 s. At the lowest position, it touched the surface of the sample with an invasion depth of 0.1 mm in 50 ms (flash heating) and was removed from the surface (fast cooling). The heating rate corresponds to ~10(4) °C/s at the filament temperature of 500 °C. The desorbed gaseous molecules were ionized by using a dielectric barrier discharge ion source, and the produced ions were detected by a time-of-flight (TOF) mass spectrometer. Less-volatile samples, such as pharmaceutical tablets, narcotics, explosives, and C60 gave molecular and protonated molecule ions as major ions with thermal decomposition minimally suppressed. For synthetic polymers (PMMA, PLA, and PS), the mass spectra reflected their backbone structures because of the suppression of the sequential thermal decompositions of the primary products. The present technique appears to be suitable for high-throughput qualitative analyses of many types of solid samples in the range from a few ng to 10 μg with minimal sample consumption. Some contribution from tribodesorption in addition to thermal desorption was suggested for the desorption processes. Figure ᅟ

We compare the dielectric spectra of aqueous MgSO4 and Na2SO4 solutions calculated from classical molecular dynamics simulations with experimental data, using an optimized thermodynamically consistent sulfate force field. Both the concentration-dependent shift of the static dielectric constant and the spectral shape match the experimental results very well for Na2SO4 solutions. For MgSO4 solutions, the simulations qualitatively reproduce the experimental observation of a slow mode, the origin of which we trace back to the ion-pair relaxation contribution via spectral decomposition. The radial distribution functions show that Mg2+ and SO42− ions form extensive water-separated—and thus strongly dipolar—ion pairs, the orientational relaxation of which provides a simple physical explanation for the prominent slow dielectric mode in MgSO4 solutions. Remarkably, the Mg2+–SO42− ion-pair relaxation extends all the way into the THz range, which we rationalize by the vibrational relaxation of tightly bound water-separated ion pairs. Thus, the relaxation of divalent ion pairs can give rise to widely separated orientational and vibrational spectroscopic features.

S quantum dots and erythrosine at λ = 532 nm was almost two orders larger. The potential applications of these quantum dots for high-order harmonic generation are discussed.

Carbon neutrality is one of the most urgent global missions and has promoted the development of clean and renewable energy sources. Sustainable photovoltaic cells have become ideal candidates for green energy harvesting owing to their high power conversion efficiencies and low production costs, which can efficiently reduce the carbon emissions. In recent years, with the increasing advancements in wearable electronics, flexible photovoltaic textile devices have been regarded as the most promising energy resources for Internet of Things. Accordingly, herein, an up‐to‐date account of the recent advancements in modern textile‐based solar cells ( i.e. , organic, perovskite, and dye‐sensitized solar cells) based on both fibers and fabrics for highly effective harvesting of solar energy is provided, and their fundamental designs and optimization strategies are comprehensively reviewed. This review emphasizes the unique characteristics, underlying mechanisms and potential applications of textile‐based solar cells. Moreover, a modern perspective on both challenges and opportunities in the advancements of the interesting textile‐based solar cells embedded in wearable devices is elucidated. This review offers new insights into advanced energy technologies and smart wearable devices that would facilitate multidisciplinary integration of basic science, device engineering, industrial applications, and other scientific domains.

The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd.

Detection and analysis of drugs-of-abuse in biological fluids are the essential tasks for the law enforcement, forensic toxicology, doping research and social health. In this work, we developed a surface-ionization mass spectrometry method for direct detection of trace amount of morphine spiked in blank urine. The mass-spectrometric analysis of spiked samples was carried out without preliminary extraction and chromatographic separation. It was found out that the major fragment ions at m/z 144, 146 could be served as indicator lines of morphine spiked in blank urine. Limit of detection of morphine spiked in blank urine was 100 pg (50 ng/ml), and a linear range of calibration curve was more than two orders of magnitude. The spiked samples were also analyzed by gas chromatography-mass spectrometry without preliminary extraction and derivatization procedures. No morphine was found in the spiked samples. The experimental data show that the high selectivity of the surface ionization can be allowed to direct analysis of morphine spiked in blank urine without its preliminary extraction and chromatographic separation.

Abstract The diamond‐wire sawing silicon waste (DWSSW) from the photovoltaic industry has been widely considered as a low‐cost raw material for lithium‐ion battery silicon‐based electrode, but the effect mechanism of impurities presents in DWSSW on lithium storage performance is still not well understood; meanwhile, it is urgent to develop a strategy for changing DWSSW particles into high‐performance electrode materials. In this work, the occurrence state of impurities presents in DWSSW was carefully analyzed using in situ Ar ion etching technology. Then, the novel Si@C@SiO x @PAl‐N–C composite was designed through in situ encapsulation strategy. The obtained Si@C@SiO x @PAl‐N–C electrode shows a high first capacity of 2343.4 mAh·g −1 with an initial Coulombic efficiency (ICE) of 84.4% under current density of 1.0 A·g −1 , and can deliver an impressive capacity of 984.9 mAh·g −1 after 200 cycles. Combined numerical simulation modeling calculations, the increase in proportion of Si 4+ /Si 0 and Si 3+ /Si 0 valence states in SiO x layer leads to a decrease in von Mises stress, which ultimately improves the cycling structural stability. Meanwhile, the porous 2D–3D aluminum/nitrogen (Al/N) co‐doped carbon layer and nanowires on SiO x layer can provide abundant active sites for lithium storage due to its developed hierarchical pores structure, which facilitates ion transport. What is more, the performance of Si@C@SiO x @PAl‐N–C//LiFePO 4 full cell shows its great potential in practical application.

RATIONALE: For public security and safety, it is highly desirable to develop an ion source for the detection of explosives that is highly sensitive, compact in size, robust, and does not use any special carrier gases such as helium. In this work, a hollow cathode discharge (HCD) ion source was developed for the detection of explosives using ambient air as a carrier gas. METHODS: To detect nonvolatile and thermally unstable explosives with high sensitivities, a new HCD ion source was designed and coupled with an ion trap mass spectrometer. RESULTS: Five explosives--hexamethylene triperoxide diamine (HMTD), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), pentaerythritol tetranitrate (PETN), nitroglycerin (NG) and trinitrotoluene (TNT)--were detected with limits of detection of lower than ng. The intensities of the NO3(-) adduct ions with RDX, PETN, and NG showed a marked increase with increase in ion source pressure in the range of 1-28 Torr. CONCLUSIONS: Because the major NOx(-) ions (x = 2, 3) produced in the plasma act as reagent ions in ion-molecule reactions of explosives, air is best suited as a carrier gas for the detection of explosives. It is proposed that the NOx(-) (x = 2, 3) and O3 contributed to the formation of [TNT-H](-) and [TNT-NO](-) ions, via the reactions NOx(-) + TNT → [TNT-H](-) + HNOx and [TNT](-) + O3 → [TNT-NO](-) + NO2 + O2.

Abstract Self‐assembled molecules (SAMs) deposited on nickel oxide (NiO x ) are the basis for achieving high‐performance inverted perovskite solar cells (PSCs). Unfortunately, the dissolution and redeposition of SAMs caused by the perovskite precursors leads to leaky monolayers, resulting in perovskite degradation and reduced stability. Here, a novel method is reported to realize strong coupling between NiO x and SAMs via inserted reductant [9tris(2‐carboxyethyl)phosphine hydrochloride (TCEP)] for an integrated NiO x ‐SAMs hole transport layer (HTL). TCEP reduces NiO x and in situ forms C═O···Ni coordinated bond and O─H···O─Ni hydrogen bond, while its ‐COOH is connected with SAM's ‐PO(OH) 2 by phosphonate and hydrogen bond, which improve the compactness of SAMs, thereby strengthening hole extraction and lowering interfacial non‐radiative recombination. Simulation calculations demonstrate that the HTL strongly coupled by TCEP has a stronger adsorption energy, significantly improving device long‐term stability. Therefore, the device based on integrated NiO x ‐SAMs HTL obtains a substantial efficiency of 26.34%. The devices maintain an impressive 97.5% of their original efficiency after 1000 h of operation under 1‐sun illumination and 90.1% after 1000 h of thermal treatment at 85 °C in nitrogen atmosphere. This work offers new horizons for designing NiO x ‐based HTLs with high SAMs coverage for high‐performance PSCs.

In this work, desorption of nonvolatile analytes induced by friction was studied. The nonvolatile compounds deposited on the perfluoroalkoxy substrate were gently touched by an ultrasonic cutter oscillating with a frequency of 40 kHz. The desorbed molecules were ionized by a dielectric barrier discharge (DBD) ion source. Efficient desorption of samples such as drugs, pharmaceuticals, amino acids, and explosives was observed. The limits of detection for these compounds were about 1 ng. Many compounds were detected in their protonated forms without undergoing significant fragmentation. When the DBD was off, no ions for the neutral samples could be detected, meaning that only desorption along with little ionization took place by the present technique.

Probe electrospray ionization (PESI) using a 0.2 mm outside diameter titanium wire was performed and the generated ions were introduced into the mass spectrometer via a discontinuous atmospheric pressure interface using a pinch valve. Time-lapse PESI mass spectra were acquired by gradually increasing delay time for the pinch valve opening with respect to the start of each electrospray event when a high voltage was applied. The opening time of the pinch valve was 20 ms. Time-resolved PESI mass spectra showed marked differences for 10 mM NaCl, 10(-5) M gramicidin S and insulin in H(2)O/CH(3)OH/CH(3)COOH/CH(3)COONH(4) (65/35/1) with and without the addition of 10 mM CH(3)COONH(4). This was ascribed to the pH change of the liquid attached to the needle caused by electrochemical reactions taking place at the interface between the metal probe and the solution. NaCl cluster ions appeared only after the depletion of analytes. For the mixed solution of 10(-5) M cytochrome c, insulin, and gramicidin S in H(2)O/CH(3)OH/CH(3)COOH (65/35/1), a sequential appearance of analyte ions in the order of cytochrome c→insulin→gramicidin S was observed. The present technique was applied to three narcotic samples; methamphetamine, morphine and codeine. Limits of detection for these compounds were 10 ppb in H(2)O/CH(3)OH (1/1) for the single sampling with a pinch valve opening time of 200 ms.

Abstract As environmentally benign and high‐efficiency energy storage devices, sodium‐ion capacitors (SICs), which combine the merits of batteries and supercapacitors, are considered to have potentially high energy/power densities and long lifespan. However, the lack of high‐rate anodes that can match the high‐power‐density cathode hinders the commercial application of SICs. In this work, heterostructured Fe/FeSe 2 /Fe 3 Se 4 nanocomposite is prepared by chemical vapor deposition (CVD) method and investigated as the anode for SICs. Through heterointerface manipulation, Fe/FeSe 2 /Fe 3 Se 4 demonstrates better sodium ion storage performances than the pure FeSe 2 and FeSe 2 /Fe 3 Se 4 . It can deliver a specific capacity of 484.8 mAh·g −1 after 100 cycles at 0.5 A·g −1 , as well as a good capacity retention. The excellent performance of Fe/FeSe 2 /Fe 3 Se 4 nanocomposite can be ascribed to the synergistic effect of the heterointerface engineered components, where FeSe 2 and Fe 3 Se 4 are responsible for offering a high capacity and metallic Fe can server as mini‐current collectors, effectively accelerating the electron and charge transfer behavior. Meanwhile, the heterointerface significantly facilitates the sodium ion fast transport, and retards the structural variation during cycling. FeSe‐1000//activated carbon (AC) SIC affords a high energy density of 112 Wh·kg −1 at 107.5 W·kg −1 , its power density can achieve 10,750 W·kg −1 with remained energy density of 44.2 Wh·kg −1 , as well as an outstanding cycling stability, demonstrating this effective heterointerface engineered anode strategy for high‐performance SICs.

ABSTRACT Cryogenic energy-dense batteries are essential for cold-climate applications. Anode-free configuration raises great opportunities for maximizing the cell-level energy density of batteries. However, high energy density of low-temperature anode-free batteries is still plagued by the lack of competent electrolytes with combined high compatibility towards metal anode and stability at high voltages. Herein, we report a high-energy-density anode-free Na battery at low temperatures via electrolyte association-dissociation equilibrium regulation. The optimized equilibrium facilitates the desolvation process and the formation of inorganic-rich anode/cathode-electrolyte interphases, thus simultaneously promoting low-temperature kinetics and high-voltage stability of the battery. Consequently, a high Coulombic efficiency (99.90%) of Na plating/stripping and a wide electrochemical stability window of electrolyte (>4.3 V) at −40°C are achieved. The anode-free Al@C||NaNi1/3Fe1/3Mn1/3O2 pouch cell delivers a record-high energy density of 204 Wh kg−1entire cell at −40°C among the reported low-temperature rechargeable batteries. This work represents a defining step for energy-dense batteries which can operate at low temperatures.

Abstract Sodium‐ion batteries (SIBs), endowed with relatively small Stokes radius and low desolvation energy of Na + , are reckoned as a promising candidate for fast‐charging endeavors. However, the C‐rate charging capability of practical energy‐dense sodium‐ion pouch cells is currently limited to ≤1 C, due to the high propensity for detrimental metallic Na plating on the hard carbon (HC) anode at elevated rates. Here, an ampere‐hour‐level sodium‐ion pouch cell capable of 3 C charging is successfully developed via phosphorus (P)‐sulfur (S) interphase chemistry. By rational electrolyte regulation, desired P−S constituents, namely, Na 3 PO 4 and Na 2 SO 4 , are generated in the solid‐electrolyte interphase with favorable Na + interface kinetics. Specifically, Na + desolvation energy barrier has been greatly lowered by the weak ion‐solvent coordination near the inner Helmholtz plane on Na 3 PO 4 interphase, while Na 2 SO 4 expedites charge carrier mobility due to its intrinsically high ionic conductivity. Consequently, an energy‐dense (126 Wh kg −1 ) O3‐Na(Ni 1/3 Fe 1/3 Mn 1/3 )O 2 ||HC pouch cell capable of 3 C charging (100 % state of charge) without Na plating can be achieved, with a great capacity retention of 91.5 % over 200 cycles. Further, the assembled power‐type Na 3 V 2 (PO 4 ) 3 ||HC pouch cell displays an impressive fast‐charging capability of 50 C, which surpasses that of previously reported high‐power SIBs. This work serves as an enlightenment for developing fast‐charging SIBs.

Abstract Enhanced high repetition rate coherent extreme ultraviolet (XUV) harmonics represent efficient probe of electron dynamics in atoms, molecules and solids. In this work, we used orthogonally-polarized two-color laser field to generate strong even and odd high order harmonics from molecular gas targets. The dynamics of odd and even harmonics from O 2 , and N 2 gases were investigated by employing single- and two-color laser fields using the fundamental radiation and second harmonic of 1030 nm, 37 fs, 50 kHz pulses. The relative efficiencies of harmonics were analyzed as a function of the thickness of the barium borate crystal used for second harmonic generation. Defocusing-assisted phase matching conditions were achieved in N 2 gas for different groups of XUV harmonics.