LED Applications Research Articles

Highly emissive 0D Tin(II) hybrid for white LED

The pursuit of environmentally friendly and highly luminescent phosphors for down-conversion white light-emitting diodes (WLEDs) remains a significant focus of research. Here, we present a novel zero-dimensional Sn(II) hybrid exhibiting vibrant orange emission peaking at 598 nm and an outstanding photoluminescence quantum yield of 69%. This hybrid, designated as (C7H8N3)4SnBr6, was synthesized via the reaction of 2-aminobenzimidazole with SnBr2, revealing distinctive self-trapped exciton emission characteristics, contributing to its broad-band emission and prolonged lifetime. Subsequently, a down-conversion WLED was constructed by integrating the Sn(II) hybrid with a green phosphor ((Sr, Ba)2SiO4:Eu2+) and a blue phosphor (BaMgAl10O17:Eu2+), resulting in CIE coordinates of (0.313, 0.331), a correlated color temperature of 6466 K, and an impressive color rendering index of 90.6. This work enriches the family of lead-free hybrid phosphors, showcasing their potential for highly efficient white LED applications.

Copper(I)‐Arsine Clusters with a Near‐Unity Phosphorescence Quantum Yield for X‐Ray Scintillation and LED Applications

AbstractRare‐earth element‐free materials that exhibit strong room temperature phosphorescence (RTP) and X‐ray scintillation properties are gaining global interest incessantly in the recent years. This work reports a series of easily synthesizable cubane Cu4I4‐triarsenic clusters [Cu4I4(R3As)3L] (L = none or nitrile), that exhibit a strong yellow‐green RTP with quantum efficiencies up to 100% and short decay times (4.4–4.9 µs). The title cluster complexes display X‐ray scintillation properties with a record ultralow detection limit (18.1 nGy s−1) and a perfectly linear dose rate response within a remarkably wide dose rate window (0–640 µGyair s−1). The cluster [Cu4I4(Ph3As)3] is highlighted as an efficient phosphor for UV‐pumped white and yellow LED devices, demonstrating an excellent white spectrum with a CIE index of (0.32,0.33) and bright yellow emission, respectively. These results may stimulate the future efforts in designing highly efficient arsenic‐based RTP materials and enriching the Cu4I4 cluster family.

Superior Quantum Efficiency Blue‐Emitting Phosphors with High Thermal Stability toward Multipurpose LED Applications

AbstractSince Bi3+‐activated phosphor are widely reported in phosphors‐converted light‐emitting diodes (pc‐LEDs), developing new‐high efficiency phosphors is imperative. Herein, superior internal quantum efficiency (IQE = 93.7%) and external quantum efficiency (EQE = 70.5%) are achieved with blue‐emitting gallate phosphor CaGdGaO4:Bi3+. Particularly, the photoluminescence excitation (PLE) spectrum ranges from 200 to 400 nm with two peaks at 337 and 368 nm, which match well with the 365 nm near ultraviolet (n‐UV) chip. The blue emission is attributed to two luminescence centers caused by Bi3+ occupying GdO6 and CaO6 sites. Furthermore, the thermal stability (@ 150 °C) enhanced from 73.2% to 80.1% when Ca2+ doping. A white LED (WLED) with high color rendering index (Ra) of 93.8 is prepared by as‐synthesized phosphors, indicating the potential application in WLED. The blue and red dual‐emitting phosphors are achieved by co‐doping Bi3+ and Eu3+. Finally, the rice planting experiment presents that the blue‐emitting can efficiently enhance the photosynthesis and seeding index of rice, which indicated these phosphors have significance in plant fill light.

Thermal transport characterization of monolayer GaN nanoribbon doped with group IV materials: An equilibrium molecular dynamics study

Bulk gallium nitride (GaN) has been considered as one of the prominent materials for a long time in the application of laser, LED and transistors. Due to its superior electrical characteristics, its low-dimensional hexagonal counterpart is currently drawing attention like graphene. In this study, we have investigated the effect of impurity atoms on the heat energy conduction within this honeycomb nanostructure of GaN to explore its scope of applications. The room temperature thermal conductivity of zigzag GaN nanoribbon (ZGaNNR) is found to be ∼ 11 Wm−1K−1 using the molecular dynamics approach with the Green-Kubo formulation. Various group IV elements namely- carbon, silicon, germanium and tin, have been incorporated within the pristine structure in four distinct doping patterns; like- point (Type-I and Type-II), pair and delta doping, to explore the thermal transport in chemically doped nanostructures. A gradual enhancement in the thermal conductivity is observed for the increasing concentration of carbon and silicon as dopants. On the other hand, selection of germanium and tin as impurity atoms suppresses the heat conduction within the crystal due to the increased low frequency phonon scattering. In all cases, Type-I point doping affects the thermal transport of ZGaNNR significantly. The narrower ribbons impede the phonon transportation due to the strong boundary effects resulting in a lower thermal conductivity. Moreover, phonon transportation is largely suppressed, and heat energy is observed to flow at a slower rate as the temperature of the ribbon rises. We have also studied these doped structures under the influence of point, edge and pair vacancies and observed a decreasing trend in thermal conductivity for each type of vacancy defect patterns introduced in the crystal. Such a study would promote the rising interest in properly characterizing the heat transport of low dimensional nanostructures and it can be an effective technique to tune the thermal conductivity of ZGaNNR for improving thermoelectric performance and thermal management in nanoscale devices.

A novel n-UV convertible colour-tunable emitting oxynitride phosphor: Realization based on Ce3+ -Tb3+ energy transfer.

In the present work, a novel n-UV convertible colour-tunable emitting phosphor was obtained based on the efficient Ce3+ -Tb3+ energy transfer in the Y10 Al2 Si3 O18 N4 host. By properly controlling the ratio of Ce3+ /Tb3+ , the colour hue of the obtained powder covered the blue and green regions, under excitation of 365 nm. The steady-state and dynamic-state luminescence measurement was performed to shed light on the related mechanism, which was justified by the electronic dipole-quadrupole dominating the related energy transfer process. Preliminary studies showed that Y10 Al2 Si3 O18 N4 :Ce3+ ,Tb3+ can be promising as an inorganic phosphor for white LED applications.

Mn2+ doped SrSn(PO4)2 nanopowder for new novel LED material

In the current work, SrSn(PO4)2 with Mn2+ doped nanopowder was prepared by solid state reaction method at temperature 950 K. Mechanically, the equipped nanopowder was characterized by structural, spectral, optical, and luminescence investigations. Crystallite size, phase of the sample was explained by powdered XRD analysis. SEM and HR-TEM analyses provided information about the average particle size of nanopowder, while EDS analysis confirmed elemental composition. The selected area electron diffraction (SAED) pattern confirmed the sample crystalline nature by means of rings corresponding to its XRD planes. FTIR study was explained by fundamental symmetric and asymmetric modes of vibrations. Optical absorption spectrum exhibited the typical Mn2+ bands in visible region. EPR studies revealed the distorted octahedral site symmetry for Mn2+. PL spectrum showed less intense emission region. The evaluated CIE co-ordinate values indicate color precipitation and CCT value is greater than 5000k which reveals that the present Mn2+:STP is useful for warm light LED applications.

White light emission in 0D halide perovskite [(CH3)3S]2SnCl6·H2O crystals through variation of doping ns2 ions

With the rapid development of white LEDs, the research of new and efficient white light emitting materials has attracted increasing attention. Zero dimensional (0D) organic–inorganic hybrid metal halide perovskites with superior luminescent property are promising candidates for LED application, due to their abundant and tailorable structure. Herein, [(CH3)3S]2SnCl6·H2O is synthesized as a host for dopant ions Bi3+ and Sb3+. The Sb3+ doped, or Bi3+/Sb3+ co-doped, [(CH3)3S]2SnCl6·H2O has a tunable optical emission spectrum by means of varying dopant ratio and excitation wavelength. As a result, we can achieve single-phase materials suitable for emission ranging from cold white light to warm white light. The intrinsic mechanism is examined in this work, to clarify the dopant effect on the optical properties. The high stability of title crystalline material, against water, oxygen and heat, makes it promising for further application.Graphical

Synthesis, structural, photoluminescence, and EPR analysis of far red emitting Ca3La2W2O12:Mn4+ inorganic phosphor for applications in plant-growth LEDs

This study explores the structural and optical properties of Mn4+ doped Ca3La2W2O12 phosphor. It also investigates the incorporation of Mn4+ ions for deep red emission and electron paramagnetic resonance (EPR) analysis. The phosphors were synthesized using the sol-gel method, and their properties were thoroughly examined using a combination of X-ray diffraction (XRD), Fourier transform infrared (FT-IR), photoluminescence (PL), and EPR technique. The XRD analysis provided insights into the phase purity, and constituents of the synthesized samples. Under 345 nm excitation, we observed far red emission at 705 nm, with the highest emission intensity occurring at a concentration of 0.0025 mol of Mn4+ metal ions in the host matrix. Concentration quenching was observed due to dipole-quadrupole interactions. The CIE chromaticity coordinates confirm far red region emission, and the estimated correlated color temperature (CCT) suggests that these phosphors can be used for bright illumination. Concurrently, the EPR examination also confirmed the presence of Mn4+ ions in the host matrix and showed the effect of variation on Mn4+ concentration in the EPR spectroscopy measurements. Furthermore, the electron paramagnetic resonance analysis demonstrated a distinctive six-line spectrum with a g-factor of approximately 1.98, indicating the presence of paramagnetic Mn4+ ions. This primary line was accompanied by a broader resonance with a linewidth of 950 Gauss, partially overlapping the six-line spectrum. The initial investigation indicates that this far red emitting phosphor can be applied to plant-growth LEDs.

Efficient Single-Phase Tunable Dual-Color Luminescence with High Quantum Yield Greater than 100% for Information Encryption and LED Applications.

In modern society, the investigation of highly efficient photoluminescent bulk materials with excitation-induced tunable multicolor luminescence and multiexciton generation (MEG) is of great significance to information security and the application of optoelectronic devices. In this study, two bulk Cu-based halide crystals of (C4H10NO)4Cu2Br5·Br and (C4H10NO)4Cu2I5·I·H2O, respectively, with one-dimensional structures were grown by a solvent evaporation method. Unexpectedly, (C4H10NO)4Cu2I5·I·H2O displayed excitation-induced tunable dual-color luminescence; one band is a brilliant green-yellow emission centered at 547 nm with a high photoluminescence quantum yield (PLQY) of up to 169.67%, and the other is a red emission at 695 nm with a PLQY of 75.76%. Just as importantly, (C4H10NO)4Cu2Br5·Br exhibits a strong broadband green-yellow emission at 561 nm under broad band excitation ranging from 252 to 350 nm, a long PL decay lifetime of 106.9 μs, and an ultrahigh PLQY of 198.22%. These materials represent the first two examples of 1D bulk crystals and Cu(I)-based halides that have a PLQY exceeding 100%. Combining the unusual luminescence characteristics with theoretical calculations reveals that MEG contributes to the green-yellow emission with ultrahigh PLQY > 100%, and that the red emission can be ascribed to [Cu2I5]3- cluster-centered emission. Additionally, an information encryption method was designed based on the Morse Code. The high luminescence characteristics of LED devices fabricated using the (C4H10NO)4Cu2Br5·Br and (C4H10NO)4Cu2I5·I·H2O crystals appear to lead to promising applications in solid-state lighting. This work extends the catalog of high-performance luminescent materials and also promotes application prospects of low-dimensional copper-based halides in optoelectronics.

Colour tunable Ca3Y2Ge3O12: Tb3+, Eu3+ phosphors with high quantum yield for white LED applications

A series of Ca3Y2Ge3O12: xTb3+, yEu3+ (CYGO) phosphors were prepared by the high-temperature solid-phase reaction method. The physical phases, luminescence properties, and energy transfer of the samples were systematically analysed and discussed by XRD and fluorescence spectroscopy. Under the excitation at 377 nm, the CYGO: xTb3+ phosphor emits green light, and the concentration quenching point of Tb3+ ions is x = 0.24. The fluorescence intensity of Tb3+ ions decrease with the increase of the concentration of Eu3+ in CYGO: xTb3+, yEu3+ phosphors, the fluorescence intensity of Eu3+ ions increase rapidly, and the luminescence colour changes from green to red with the increasing of the concentration of Tb3+ at a certain concentration of Tb3+, the luminescence colour changes from green to red, confirm the existence of an energy transfer process between Tb3+ and Eu3+. The energy transfer mechanism is quadrupole-quadrupole interaction. The quantum yield is as high as 95.45%. Under the excitation of the UV-LED chip at 370 nm, the LED based on CYGO:0.24 Tb3+, 0.08Eu3+ phosphors have a Ra of 86.7, low CCT of 4917 K and CIE coordinate of (0.3498,0.3789), so the CYGO: xTb3+, yEu3+ phosphors have a potential for application in the field of UV-near-UV white LEDs. has a certain application potential.

Preparation of BaSi2O2N2:Eu2+ cyan phosphor with excellent luminescence properties via heterogeneous precipitation method for high-CRI white LED applications

Preparation of BaSi2O2N2:Eu2+ cyan phosphor with excellent luminescence properties via heterogeneous precipitation method for high-CRI white LED applications

Broadband NIR luminescence of Cr3+-doped Mg4Nb2O9 phosphors toward LED light source applications for NIR spectrometry

Abstract Herein, we report the photoluminescence (PL) properties of Cr3+-doped Mg4Nb2O9 phosphors for applications in NIR phosphor-converted LEDs. Trigonal Mg4Nb2O9 crystals with Cr3+ substitution at three sites were synthesized as the main phase using a solid-state reaction. X-ray photoelectron spectrometry and diffuse reflectance spectroscopy indicated that only trivalent chromium ions were present in the samples. Broadband NIR emission of Cr3+ suitable for combination with Si photodetectors was confirmed at approximately 850 nm. The maximum PL quantum yield (PLQY) was 0.62, and concentration quenching explained the Cr concentration dependence of the PLQY and PL decay time. Low-temperature PL measurements suggested that the PL spectrum comprised three distinct emission bands. The results of the phonon line simulation, low-temperature PL excitation measurements, and crystal-field parameter estimation clarified the correlation between these emission bands and the Cr3+ substitution sites.

Unveiling the luminescence property of Pr-incorporated barium cerate perovskites for white LED applications

Abstract The various structural and conductive attributes of barium cerate, BaCeO3 position it as a highly promising matrix for energy storage purposes. The current study illustrates that barium cerate can be effectively tailored by introducing trivalent praseodymium ions, thereby enhancing its optical properties as well. In this work, single-phased orthorhombic crystalline powders of barium cerate incorporated with Pr3+ (BaCeO3: Pr3+) were synthesized using the gel combustion procedure, followed by calcination. We conducted a comprehensive investigation into their crystal structure, vibrational characteristics, optical properties, and potential applications in wLEDs. The structure refinement indicates that Pr3+ occupies Ce4+ site, which results in the expansion of the cell and facilitates the generation of defects such as Pr Ce ′ ${\mathrm{Pr}}_{\text{Ce}}^{\prime }$ and oxygen vacancies V O ⋅ ⋅ ${V}_{\text{O}}^{\cdot \cdot }$ . By correlating information gathered from diffuse reflectance spectra with that obtained from photoluminescence spectra, we gained a deeper understanding of the electronic level structure and the mechanism of energy transfer. We successfully achieved a finely tuned cool white light emission with very low color purity (CP), a high color rendering index (CRI), and a high correlated color temperature (CCT) with a quantum efficiency of 36.3 % by exciting the material with a 321 nm wavelength. Because of the transfer of energy within activators through dipole–dipole interaction, luminescence quenching occurs when Pr3+ concentration reaches 1 wt%. To the best of our knowledge, this is the initial investigation of luminescence properties of Pr-incorporated barium cerate perovskites.

Bidirectional energy transfer in yellow-emitting Gd2WTiO8:Er3+,Sm3+ phosphors for white and NIR LEDs applications

Energy transfer between rare earth ions is a well-established strategy for achieving controlled and tunable emission in phosphors. Previous researches have reported tunable photoluminescence in Er3+ and Sm3+ co-doped phosphors by altering their concentration ratio. However, whether there is energy transfer between Er3+ and Sm3+ is still controversial. Hence, it is of great significant to reveal the underlying mechanism of energy transfer between Er3+ and Sm3+, which is conducive to the development of rare-earth activated phosphors. In this work, we employ the scheelite compound of Gd2WTiO8 as the host, Er3+ and Sm3+ as the activators to prepare color-tunable Gd2WTiO8:Er3+,Sm3+ phosphors and comprehensively study the energy transfer process between Er3+ and Sm3+. Though analysis of photoluminescence excitation, emission spectra, and decay curves, a bidirectional energy transfer process involving four cross-relaxation events between Er3+ and Sm3+ is uncovered. Due to this bidirectional energy transfer, Er3+ and Sm3+ mutually quench each other's luminescence. Excitation peaks of Sm3+ are specifically quenched at 378, 489, and 520 nm, ascribed to the distinct differences in absorption and energy transfer efficiency between Er3+ and Sm3+. Tunable emission from green to orange-red is obtained in Gd2WTiO8:Er3+,Sm3+ phosphors by adjusting the co-doped concentration of Er3+ and Sm3+. The phosphor has excellent thermal stability, retaining 82.33 % of its integral intensity for visible light emission at 423 K compared to room temperature. A phosphor-converted light-emitting diode (pc-LED) using Gd2WTiO8:Er3+,Sm3+ as a yellow-emitting component has been fabricated. This white pc-LED achieves a color rendering index of 87.5 for lighting and emits infrared emission for night vision applications. This study will offer crucial backing in the advancement of phosphors doped with rare earth elements.

Synthesis, characterization, and enhanced photoluminescence of ZrO2:Dy3+ phosphors by incorporating Li+, Na+ and K+ ions for LED applications

ZrO2:(0.01)Dy3+:xA+ (A = Li+, Na+ and K+) phosphors were prepared by one step solution combustion method. X-ray diffraction (XRD), reveal formation of different phases. Functional group presence and its vibrations are assigned from FTIR measurements. Influence of alkali metal ions (A+) on surface morphology were realized from SEM micrograph. XPS study was carried out to confirm the presence of Li+ ions. Photoluminescence (PL) spectra of the samples excited at 350 nm exhibited two strong emission peaks at 480 nm and 580 nm, which are characteristic transitions of Dy3+ ions. However, the relative intensity between these peaks varies considerably due to the variation of the co-dopant/compensator (Li+, Na+, K+) concentration, representing the variation of the crystal field. Effects of different charge compensators (A+) and their concentration on the structural and luminescence properties of ZrO2:(0.01)Dy3+:xA+ phosphors were thoroughly investigated. Further, Judd-Ofelt parameters were calculated. Total emission colour (TEC) concentration of ZrO2:(0.01)Dy3+ phosphors were improved remarkably with the addition of charge compensators (A+), which would promote their applications in solid state lighting. The effective blue emission of the phosphors was changing with different co-dopant incorporation. Implying possible use of this material as a blue emitting phosphor as a blue emitting component in three-component white light-emitting diodes (WLEDs).

Near-infrared light driven highly efficient and thermally stable Gd2Ti2O7:Er3+/Yb3+ sub-microspheres for photocatalytic and plant growth LED applications

Photocatalysis is a technique that can help address various global challenges of energy and environment by utilizing solar energy. Photocatalysts that can capture light from different regions of the electromagnetic spectrum, such as ultraviolet, visible or near-infrared, are required to optimize the use of solar energy. Therefore, researchers have been developing various strategies to design such photocatalysts. Herein, we report the NIR-induced photocatalytic performance of pyrochlore-structured Gd2Ti2O7:1Er3+/10Yb3+ (GT:Er3+/Yb3+) sub-microspheres by using rhodamine B (RhB), a commom organic dye, as a probe molecule. A facile solvothermal process was used to prepare the sub-microspheres that emitted strong red light when irradiated by a 980 nm laser. The luminescence mechanism was attributed to cross-relaxation and back energy transfer processes. Furthermore, the GT:Er3+/Yb3+ sub-microspheres exhibited remarkable thermal stability and durability under 980 nm laser irradiation and the catalytic studies showed in the presence of laser light of only 1 W input power. The sub-microspheres completely broke down RhB dye into H2O and CO2 in 10 h. This study offers a novel approach to exploit NIR-driven lanthanide materials for LED and photocatalytic applications.

Structural and luminescent properties of Sr2SiO4 phosphors doped with Eu2+ and Ce3+ ions for advanced LED applications

Eu2+ and Ce3+ ions with different concentrations of single/co-doped Sr2SiO4 phosphors have been successfully prepared using a high-temperature solid-state reaction. The influences of Eu2+ and Ce3+ ions on the construction and optical performance behavior of Sr2SiO4 have been investigated by X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), scanning electron microscope (SEM), ultra-violet-visible (UV–vis), and photoluminescence (PL) spectral analyses. XRD results revealed that the doping ions have entered the host lattice, and SEM showed the crystallite sizes have been found to vary from 1 to 6 μm. The intensity of the absorption spectra for the co-doped samples was larger than that of the single-doped sample. PL spectra displayed that the emission intensity of the samples strengthened as the amount of concentrations of Eu2+ and Ce3+ ions. The concentration quenching of single/co-doped phosphors was related to dipole-dipole interaction, and the energy from the 2F5/2 transition to the 5D level of Ce3+ was effectively transferred to the 4f65d level of Eu2+. The Eu2+ and Ce3+ ions co-doping samples resulted in a light green color. The findings from the study reveal that the Eu2+ and Ce3+ ions single/co-doped Sr2SiO4 phosphors would be potential candidates for the LED application.

Tunable light emission of Bi and V-doped borosilicate glasses for application in white light-emitting diodes

Melt-quenched borosilicate glasses, co-doped with Bi and V ions, exhibited broad visible spectrum emissions. Bi ions primarily existed as Bi3+, acting as network modifiers, lowering the glass transition temperature linearly with increasing Bi content. V5+ ions adopted tetrahedral coordination as [VO4]3- units. Photoluminescence of Bi ions is shifted from blue to longer wavelengths with higher Bi content, associated with the stabilization of Bi2+ and the presence of Bi3+ in different local environments. Combined with V ions, the glasses emitted light covering the entire visible spectrum, offering the potential for white LED applications with correlated color temperatures ranging from 6135 to 4010 K. The highest QY was 11.9 and 8.0 % upon excitation at 325 and 340 nm.

A novel bismuth-activated Sr3NaSbO6 phosphor with multi-band switchable emission for NUV-pumped LEDs.

Multi-band emission characteristics open up more possibilities for the application of phosphors in LEDs. In this work, a novel Bi3+-activated Sr3NaSbO6 phosphor is developed. The Bi3+ occupation, luminescence properties and application in LEDs of the phosphor are investigated and discussed. There are Sr and Na sites in the crystal structure for Bi3+ substitution, corresponding to two different luminescence centers, which can be excited by commercial UV chips. By changing the excitation wavelength, Bi3+ in the two lattice sites can be excited separately, and a switchable multi-band emission can be obtained accordingly. The blue emission peaks at 450 nm, and the other emission has an ultra-wide full-width at half-maximum of 206 nm, which can cover a wider visible spectrum. All the results show that the phosphor has application prospects in LEDs.

Synthesis of a new potassium-substituted lead fluorapatite and its structural characterization.

Prismatic crystals of partially potassium substituted lead fluorapatite Pb5.09Ca3.78K1.13(PO4)6F0.87 were grown through a solid-state reaction. The structural study conducted by single-crystal X-ray diffraction revealed that the compound crystallizes in the hexagonal P63/m space group, with unit cell parameters a = b = 9.7190(5) Å, c = 7.1700(6) Å and V = 587.37(7) Å3(Z = 1), as well as final values amounting to R and wR of 0.0309 and 0.0546, respectively. The structural refinement demonstrated that Pb occupies both the (6h) and (4f) structural sites of hexagonal fluorapatite, K occupies the (6h) site, and Ca is placed on the (4f) site. Powder X-ray diffraction study indicated the absence of additional phases or impurities. Chemical analysis using atomic absorption spectrometry and energy-dispersive X-ray spectroscopy confirmed the expected chemical formula. The electrical conductivity measured over a wide temperature range was found to be governed by the ion mobility mechanism in the tunnel along the c axis (probably attributed to the fluorine ion located there). We, therefore, could infer from the analysis of the complex impedance spectra that the electrical conductivity of our apatite depends essentially on the temperature and frequency, which produces a relaxation phenomenon and semiconductor-like behavior. Moreover, the strong absorption in the UV-Visible region was substantiated through studies of the optical properties of the developed sample. Fluorescence spectra exhibited emissions in the orange regions when excited at 375 nm. The findings of the phenomena resulting from the emission and conduction of the apatite in question suggest its potential for application in various technological fields such as photovoltaic cells, optoelectronics, photonics, LED applications, catalysis and batteries.