Perpendicular magnetic anisotropy is important for increasing the information storage density in the perpendicular magnetic recording media, and for rare earth-transition metal alloys with bulk perpendicular magnetic anisotropy that generate great research interest due to their abundant interesting phenomena, such as fast domain wall motion and skyrmion. Here, we deposit amorphous GdFe ferrimagnetic films on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 ferroelectric substrate and investigate the effect of electric-field-induced piezostrain on its bulk perpendicular magnetic anisotropy. The anomalous Hall effect and polar Kerr image measurements suggest an enhanced bulk perpendicular magnetic anisotropy by electric field, which originates from a positive magnetoelastic anisotropy due to the positive magnetostriction coefficient of the GdFe film and the electric-field-induced tensile strain along the z axis in Pb(Mg1/3Nb2/3)0.7Ti0.3O3 ferroelectric substrate. Our results enrich the electrical control of perpendicular magnetic anisotropy and are useful for designing spintronic devices based on perpendicular magnetic anisotropy.

Herein, two donors based on fluorine substituted isatin units (DI3T-1F, DI3T-2F) were compared with the mixture of PC71BM for thick-film small molecule solar cells. The devices based on DI3T-1F demonstrate balanced charge transportand less trap-assisted recombination, leading to higher PCE of 8.33% witha thickness ca.150 nm compared to DI3F-2F (PCE of 7.32% with thick film at ca. 160 nm) without additives, solvent or thermal annealing treatments. Both devices based on small molecule:fullerene blends demonstrate good tolerance to active layer thickness from 150 to 300 nm. Our results indicate that less fluorine atoms on donor units can optimize the charge transport, phase-segregated morphology in small molecule solar cells without the need for post-treatment.

We report the development of highly efficient and stable solution-processed organic light emitting transistors (OLETs) that combine a polymer heterostructure with the transparent high-k dielectric poly(vinylidenefluoride0.62-trifluoroethylene0.31-chlorotrifluoroethylene0.7) (P(VDF-TrFE-CTFE)). The polymer heterostructure comprises of the poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b’]dithiophen-2-yl)-alt-[1,2,5]thiadiazolo[3,4-c]pyridine] (PCDTPT) and Super Yellow as charge transporting and light emitting layers, respectively. Device characterization shows that the use of P(VDF-TrFE-CTFE) leads to larger channel currents (≈2 mA) and lower operating voltages (-35 V) than for previously reported polymer based OLETs. Furthermore, the combined transparency of the dielectric and gate electrode, results in efficient bottom emission with external quantum efficiency of ≈0.88 % at a luminance L ≥ 2000 cd m−2. Importantly, the resulting OLETs exhibit excellent shelf life and operational stability. The present work represents a significant step forward in the pursuit of all-solution-processed OLET technology for lighting and display applications.

Freestanding cathodes with a high sulfur loading more than 4 mg cm−2 are essential for practical high-energy density Li–S batteries. However, Li+ transport is sluggish and polysulfide shuttling is serious in thick cathodes, leading to rapid capacity loss and inferior rate performance. Herein, an asymmetric Li–S cathode threaded with positive charges networks was introduced by a facile phase separation strategy coupled with cationic-crosslinking method. This large-area and flexible cathode membrane shows a gradient distribution of pore structure with a skin sieving layer supported on a thick porous submatrix. This dual sulfur host reveals an inbuilt ability to suppress polysulfide shuttling in Li–S cells. Meanwhile, the positive charge networks derived from post-crosslinking endows the cathode frameworks with boosted Sn2− trapping ability and enhanced ionic transport kinetics. Further adjustment of the cationic networks reveals its ionic exchange mechanism in accelerating the redox reactions at the positive charge interface. As a result, composite membrane with high sulfur loading (9.1 mg cm−2) yields a capacity of over 8.1 mAh cm−2 for long-term cycling. This scalable and functional asymmetric cathode design presents an alternative route toward high energy density Li−S batteries.

Integrating multiple functionalities into a single device is a striking field in metasurfaces. One promising aspect is polarization-dependent meta-devices enabled by simultaneous phase control over orthogonally polarized waves. Among these, Pancharatnam-Berry (PB) metasurfaces have drawn enormous interest owing to their natural and robust phase control ability over different circularly polarized waves. However, the phase responses are locked to be opposite with each other, resulting in interrelated functionalities under the circularly polarized incidence. Here, a generic designing method based on transmission-type dielectric metasurfaces is proposed in the terahertz regime, which breaks this relation by further incorporating dynamic phase with geometric phase, namely, spin-decoupled phase control method. We demonstrate this method by designing and characterizing an efficient multifunctional meta-grating, which splits different circularly polarized waves to asymmetric angles under normal incidences. More importantly, we promote this method by designing several multiplexed meta-gratings for applications of asymmetric polarization generation, which can convert arbitrary linearly polarized wave to two different linearly polarized waves with nearly equal strength and split them to asymmetric angles with a polarization-insensitive efficiency. The designing strategy proposed here shows an impressive robustness and a great flexibility for designing multifunctional metasurface-based devices and opens new avenues toward modulation of polarization states and the application of metasurfaces in beam steering and polarization multiplexing systems.

Half-Heusler compounds have attracted considerable attention due to their fantastic physical properties that include topological effects,Weyl fermions, unusual magnetism, and superconductivity. Herein, the transport properties of half-Heusler ScPdBi single crystals are studiedacross a wide temperature range and different magnetic fields. From the field-dependent magnetoresistance, we observe a clear weak antiloc-alization (WAL) effect below 200 K in the low magnetic-field region. The angle-dependent magnetoconductance and the ultralarge prefactoraextracted from the Hikami-Larkin-Nagaoka equation reveal that the WAL effect is a 3D bulk effect caused by strong spin–orbit coupling.We further studied the magnetotransport properties of the single crystal upon application of hydrostatic pressure and found that the energygap of ScPdBi increases gradually as the hydrostatic pressure increases. Density functional theory calculations confirm that applying hydro-static pressure decreases the lattice parameters and, consequently, enlarges the bandgap

Vanadium-based compounds have been widely used as electrode materials in aqueous zinc ion batteries (ZIBs) due to the multiple oxidation states of vanadium and their open framework structure. However, the solubility of vanadium in aqueous electrolytes and the formation of byproducts during the charge/discharge process cause severe capacity fading and limit cycle life. Here, we report an ultrathin HfO2 film as an artificial solid electrolyte interphase (SEI) that is uniformly and conformally deposited by atomic layer deposition (ALD). The inactive hafnium(IV) oxide (HfO2) film not only decreases byproduct (Zn4SO4(OH)6·xH2O) formation on the surface of Zn3V2O7(OH)2·2H2O (ZVO) but also suppresses the ZVO cathode dissolution in the electrolyte. As a result, the obtained HfO2-coated ZVO cathodes deliver higher capacity and better cycle life (227 mAh g–1@100 mA g–1, 90% retention over 100 cycles) compared with pristine ZVO (170 mAh g–1@100 mA g–1, 45% retention over 100 cycles). A mechanistic investigation of the role of HfO2 is presented, along with data showing that our method constitutes a general strategy for other cathodes to enhance their performance in aqueous ZIBs.

Solid electrolyte interphase (SEI)-forming agents such as vinylene carbonate, sulfone, and cyclic sulfate are commonly believed to be film-forming additives in lithium-ion batteries that help to enhance graphite anode stability. However, we find that the film-forming effect and the resultant SEI may not be the only reasons for the enhanced graphite stability. This is because the as-formed SEI cannot inhibit Li+–solvent co-intercalation once the additive is removed from the electrolyte. Instead, we show that the Li+ solvation structure, which is modified by these additives, plays a critical role in achieving reversible Li+ (de)intercalation within graphite. This discovery is confirmed in both carbonate and ether-based electrolytes. We show that the problem of graphite exfoliation caused by Li+–solvent co-intercalation can be mitigated by adding ethene sulfate to tune the Li+ coordination structure. This work brings new insight into the role of additives in electrolytes, expanding the prevailing thinking over the past 2 decades. In addition, this finding can guide the design of more versatile electrolytes for advanced rechargeable metal-ion batteries.

Methylammonium lead halide perovskites have gained a lot of attention because of their remarkable physical properties and potential for numerous (opto)electronic applications. Here, high-performance photodetectors based on CH3NH3PbI3 (MAPbI3)/CdS heterostructures are demonstrated. The resulting self-powered MAPbI3/CdS photodetectors show excellent operating characteristics including a maximum detectivity of 2.3 × 1011 Jones with a responsivity of 0.43 A/W measured at 730 nm. A temporal response time of less than 14 ms was achieved. The mechanisms of charge separation and transport at the interface of the MAPbI3/CdS junction were investigated via conductive atomic force microscopy (AFM) and photoconductive AFM. Obtained results show that grain boundaries exhibit higher photocurrent than flat regions of the top perovskite layer, which indicates that excitons preferentially separate at the grain boundaries of the perovskite thin film, that is, at the edges of the MAPbI3 crystals. The study of the photoelectric mechanism at the nanoscale suggests the device performance could potentially be fine-tuned through grain boundary engineering, which provides essential insights for the fabrication of the high-performance photodetector. The demonstrated self-powered photodetector is promising for numerous applications in low-energy consumption optoelectronic devices.

We fabricated gold nanoparticles on nanoporous silicon microparticles using electroless deposition in a hydrofluoric acid solution containing gold chloride. The reaction was followed by UV spectrometer analysis of the absorbance of the solution (proportional to the nanoparticle concentration) for two temperatures (20 and 50 °C). The results indicate that the process is autocatalytic, described by a pseudo-first-order reaction, the apparent rate constant kobs of which was determined by utilizing UV spectrometer data. We found that the reaction rate constant at 20 °C is 7 × 10-3 s-1 and that at 50 °C is 2.9 × 10-2 s-1. Scanning electron microscope (SEM) analysis of samples and diffusion-limited aggregation (DLA) simulations were used to validate the results. This study aims to resolve the kinetics of the electroless deposition of gold on silicon at the nanoscale, in the present state of art missing a quantitative characterization, for certain conditions of growth and given values of temperature and concentration of the reagents. Results may have applications to the synthesis of gold nanoparticles and their use as nanosensors, drug delivery systems, or metal nanometamaterials with advanced optical properties.