Broad-Temperature Thermoelectric Figure of Merit Enhancement in Unconventional n-Type BiTeSe Alloys.

BiTeSe-based alloys are conventional n-type thermoelectric materials for solid-state cooling and heat harvest near room temperature; high thermoelectric performance over a wide temperature range and superior mechanical properties are essential for their use in practical thermoelectric devices. In this work, we demonstrated that decent thermoelectric performance can also be realized in an unconventional composite with a nominal composition of BiTeSe since the emergence of a BiTeSe phase with Se ordered occupation could induce an enlargement of the electronic band gap. Follow-up Cu/Na codoping could generate a dynamic optimization of carrier concentration, significantly broadening the temperature range of high thermoelectric performance.

Thermoelectric Cooling-Oriented Large Power Factor Realized in N-Type BiTe Via Deformation Potential Modulation and Giant Deformation.

Thermoelectric refrigeration, utilizing Peltier effect, has great potential in all-solid-state active cooling field near room temperature. The performance of a thermoelectric cooling device is highly determined by the power factor of consisting materials besides the figure of merit. In this work, it is demonstrated that successive addition of Cu and Nd can realize non-trivial modulation of deformation potential in n-type room temperature thermoelectric material BiTeSe and result in a significant increment of electron mobility and remarkably enhanced power factor.

Enhanced photovoltaic performance of silicon solar cells using a down-shift KCaMg(VO) phosphor.

The efficiency of silicon solar cells is still lower than theoretical values, partly due to their inability to utilize the ultraviolet and infrared portions of the solar spectrum. Herein, a novel method using a KCaMg(VO) phosphor with a down-shift effect to improve the photovoltaic performance of silicon solar cells and enhance the utilization of UV light in standard p-type silicon solar cells is proposed. The synthesized phosphors were mixed with an ethylene vinyl acetate (EVA) copolymer and pressed into a film, which was subsequently encapsulated in monocrystalline silicon solar cells.

Interlamellar-Spacing Engineering of Stable and Toxicity-Reduced 2D Perovskite Single Crystal for High-Resolution X-ray Imaging.

Two-dimensional (2D) lead halide perovskites are excellent candidates for X-ray detection due to their high resistivity, high ion migration barrier, and large X-ray absorption coefficients. However, the high toxicity and long interlamellar distance of the 2D perovskites limit their wide application in high sensitivity X-ray detection. Herein, we demonstrate stable and toxicity-reduced 2D perovskite single crystals (SCs) realized by interlamellar-spacing engineering via a distortion self-balancing strategy.

Realizing Outstanding Energy Storage Performance in KBT-Based Lead-Free Ceramics via Suppressing Space Charge Accumulation.

The great potential of KBiTiO (KBT) for dielectric energy storage ceramics is impeded by its low dielectric breakdown strength, thereby limiting its utilization of high polarization. This study develops a novel composition, 0.83KBT-0.

Giant Deformation Induced Staggered-Layer Structure Promoting the Thermoelectric and Mechanical Performance in n-Type Bi(Te, Se).

Bismuth telluride has long been recognized as the most promising near-room temperature thermoelectric material for commercial application; however, the thermoelectric performance for n-type Bi(Te, Se)-based alloys is far lagging behind that of its p-type counterpart. In this work, a giant hot deformation (GD) process is implemented in an optimized BiTeSeI+3 wt%KBiSe precursor and generates a unique staggered-layer structure. The staggered-layered structure, which is only observed in severely deformed crystals, exhibits a preferential scattering on heat-carrying phonons rather than charge-carrying electrons, thus resulting in an ultralow lattice thermal conductivity while retaining high-weight carrier mobility.

Giant dielectric response and relaxation behavior of Bi/W co-doped TiO ceramics.

With the rapid development of electronic information technology, dielectric ceramics are widely used in the field of passive devices such as multi-layer ceramic capacitors. In this paper, (BiW)TiO (BWTO) ceramics with superior dielectric properties have been prepared by using a traditional solid-state method. Remarkably, at a (BiW) doping level of 0.

Zeolite-like Topology Oxonitridosilicate LaBaSiNO with Potential Applications in Nonlinear Optical Materials.

A novel zeolite-like topology oxonitridosilicate LaBaSiNO with the space group 2 (no. 38) and lattice parameters = 9.5193 (3) Å, = 16.

BaLaVON: a novel anti-perovskite oxynitride for electrode applications.

The exploration of transition metal oxynitrides has garnered significant interest due to their intriguing property diversity. Herein, we present a promising new transition metal oxynitride BaLaVON, which features an anti-perovskite structure type. This unique structural configuration endows the material with remarkable conductivity, particularly at low temperatures, paving the way for the material to be used in a wide range of technological applications.

Enhancing Energy Storage Performance in Lead-Free Bismuth Sodium Niobate-Based Tungsten Bronze Ceramics through Relaxor Tuning.

A series of tungsten bronze SrNaBiNbTaO (SBNN-Ta) ferroelectric ceramics were designed and synthesized by the traditional solid-phase reaction method. The B-site engineering strategy was utilized to induce structural distortion, order-disorder distribution, and polarization modulation to enhance relaxor behavior. Through investigating the impact of B-site Ta replacement on the structure, relaxor behavior, and energy storage performance, this study has shed light on the two main factors for relaxor nature: (1) with the increase of Ta substitution, the tungsten bronze crystal distortion and expansion induced the structural change from an orthorhombic 2 phase to 2 phase at room temperature; (2) the transition from ferroelectric to relaxor behavior could be attributed to the coordinate incommensurate local superstructural modulations and the generation of nanodomain structure regions.

The origin of dielectric relaxation behavior in TiO based ceramics co-doped with Zn, W ions under a N/O sintering atmosphere.

Dense (ZnW)TiO (ZWTO) ceramics were fabricated using a conventional solid state reaction method with sintering under a nitrogen atmosphere (ZWTO-N) and an oxygen atmosphere (ZWTO-O), respectively. Colossal permittivity ( > 10) and low loss (tan  < 0.1) were simultaneously achieved in ZWTO-N ceramics, and two types of dielectric relaxation behaviors observed were interpreted to be due to interface polarization and disassociation between oxygen vacancies and trivalent titanium ions, respectively.

Superior Energy Storage Properties and Optical Transparency in K Na NbO -Based Dielectric Ceramics via Multiple Synergistic Strategies.

Eco-friendly transparent dielectric ceramics with superior energy storage properties are highly desirable in various transparent energy-storage electronic devices, ranging from advanced transparent pulse capacitors to electro-optical multifunctional devices. However, the collaborative improvement of energy storage properties and optical transparency in KNN-based ceramics still remains challenging. To address this issue, multiple synergistic strategies are proposed, such as refining the grain size, introducing polar nanoregions, and inducing a high-symmetry phase structure.

All Cubic-Phase δ-TAGS Thermoelectrics Over the Entire Mid-Temperature Range.

GeTe-based pseudo-binary (GeTe) (AgSbTe ) (TAGS-x) is recognized as a promising p-type mid-temperature thermoelectric material with outstanding thermoelectric performance; nevertheless, its intrinsic structural transition and metastable microstructure (due to Ag/Sb/Ge localization) restrict the long-time application of TAGS-x in practical thermoelectric devices. In this work, a series of non-stoichiometric (GeTe) (Ag Sb Te ) (x = 85∼50; δ = ≈0.20-0.

Significantly Enhanced Thermoelectric Performance Achieved in CuGaTe through Dual-Element Permutations at Cation Sites.

CuGaTe has become a widely studied mid-temperature thermoelectric material due to the advantages of large element abundance, proper band gap, and intrinsically high Seebeck coefficient. However, the intrinsically high lattice thermal conductivity and low room-temperature electrical conductivity result in a merely moderate thermoelectric performance for pristine CuGaTe. In this work, we found that Cu deficiency can significantly reduce the activation energy of Cu vacancies from ∼0.

Synthesis and luminescence properties of new nitridolithosilicate phosphor LaBaLiSiN:Pr grown in Li flux.

Flux synthesis is an effective method to discover large crystals of new compounds. In this paper, a solid-state reaction in Li flux produced a new nitridolithosilicate LaBaLiSiN in the orthorhombic space group (No. 63) with lattice parameters of = 9.

Strained Endotaxial PbS Nanoprecipitates Boosting Ultrahigh Thermoelectric Quality Factor in n-Type PbTe As-Cast Ingots.

Lead telluride (PbTe) has long been regarded as an excellent thermoelectric material at intermediate temperature range (573-873 K); however, n-type PbTe's performance is always relatively inferior to its p-type counterpart mainly due to their different electronic band structures. In this work, an ultrahigh thermoelectric quality factor (µ/κ  ≈ 1.36 × 10 cm KJ V ) is reported in extra 0.

Narrow-band red emitting oxonitridosilicate phosphor LaSrSiNO:Pr (x≈ 1.69).

The new oxonitridosilicates LnSrSiNO (Ln = La, Ce) were synthesized by high temperature solid-state reactions. The crystal structures were solved and refined from both single-crystal and powder X-ray diffraction data. These oxonitridosilicate compounds crystallize in the monoclinic space group P2/n (no.

Multi-inch single-crystalline perovskite membrane for high-detectivity flexible photosensors.

Single crystalline perovskites exhibit high optical absorption, long carrier lifetime, large carrier mobility, low trap-state-density and high defect tolerance. Unfortunately, all single crystalline perovskites attained so far are limited to bulk single crystals and small area wafers. As such, it is impossible to design highly demanded flexible single-crystalline electronics and wearable devices including displays, touch sensing devices, transistors, etc.

Narrow-band blue emitting nitridomagnesosilicate phosphor SrMgSiN:Eu for phosphor-converted LEDs.

We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+.

First-principles calculations of electrical properties, structure, and phase transition of KNaNbO solid solutions.

The structure, total energy and orthorhombic as well as tetragonal electronic properties of KNaNbO (KNN) as a function of Na concentration were studied with first principles calculations. When the Na content of KNN was gradually increased the orthogonal phase transformation occurred, which produced an enhanced piezoelectric response of the tetragonal KNN. This result proved that the high d originated from the phase transition.

Controlled assembly of Fe3O4 magnetic nanoparticles on graphene oxide.

We describe a facile approach to controllable assembly of monodisperse Fe(3)O(4) nanoparticles (NPs) on chemically reduced graphene oxide (rGO). First, reduction and functionalization of GO by polyetheylenimine (PEI) were achieved simultaneously by simply heating the PEI and GO mixture at 60 °C for 12 h. The process is environmentally friendly and convenient compared with previously reported methods.

Preparation and capacitance property of MnO2-pillared Ni(2+)-Fe3+ layered double hydroxides nanocomposite.

A novel MnO(2)-pillared Ni(2+)-Fe(3+) layered double hydroxides nanocomposite has been successfully fabricated using an intercalation/reduction reaction followed by heating treatment. The structural evolution of the samples obtained at different stages has been characterized by XRD, TEM, XPS, IR and N(2) adsorption-desorption. The layered structure of MnO(2)-pillared Ni(2+)-Fe(3+) layered double hydroxides nanocomposite can be maintained at 300 °C, and the obtained material has a large surface area of 202 m(2) g(-1).