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Silicon is a promising photocathode material for solar hydrogen evolution because of its small band gap, negative conduction band position, and ideal theoretical current density. In this study, p-type Si microwire ( p -Si MW) arrays were prepared as photocathodes because of the large surface area and high light-harvesting capability. However, Si MWs suffered from low photocatalytic activity because of slow photo-induced carriers during driving of water-splitting reaction. Therefore, molybdenum sulfide (MoS 2 ) with appropriate band alignment with p-Si material was employed for surface modification to function as a co-catalyst for collecting photo-generated minority carriers and reducing recombination possibility. The onset potential and current density at 0 V versus reversible hydrogen electrode (RHE) of Si@MoS 2 MWs were +0.122 V and −8.41 mA cm −2 . Heterometal atoms were employed to dope MoS 2 co-catalyst and expose more sulfur-terminated active sites to further boost photoelectrochemical performance. Optimal activity of Si@MMoS x (M = Fe, Co, Ni) was achieved by doping Co heteroatoms, and its turn-on voltage and photocurrent density at 0 V (vs. RHE) were respectively increased to +0.192 V and −17.2 mA cm −2 . X-ray absorption spectroscopy was applied to demonstrate that Fe ions of FeMoS x were dichalcogenide materials, forming a composite with MoS 2 and contributing better photoelectrolytic efficiency. By contrast, two-valent heteroatoms of CoMoS x and NiMoS x substituted the Mo 4+ ions in MoS 2 . For charge compensation, more defects and edges were revealed as active sites of solar hydrogen production by adding Co or Ni dopants in MoS 2 co-catalyst, which led to lower overpotential. [ABSTRACT FROM AUTHOR]

Utilizing CO 2 as cathode gas, Na–CO 2 battery has been intensively studied due to its potential application in the exploration of Mars, where CO 2 takes up 96% of the atmosphere. However, evaporation of the flammable liquid electrolyte restricts the practical application of the Na–CO 2 battery. Herein, a solid-state Na–CO 2 battery has been fabricated with the help of a plastic crystal electrolyte and kinetically stable interphase. The succinonitrile-based plastic crystal electrolyte interphase makes an intimate contact between Na 3 Zr 2 Si 2 PO 12 (NZSP) and cathode, thereby promotes the interfacial charge transfer. Simultaneously, the kinetically stable interphase on the anode side is revealed by the cooperation of theoretical calculation and experiments. The kinetically stable interphase protects the NZSP from the continuous interfacial parasitic reaction. The as-proposed solid-state Na–CO 2 battery delivers a life span of 50 cycles at 100 mA g−1 with a potential gap of 1.4 V. This study makes solid-state electrolyte Na–CO 2 battery an attractive prospect in future applications. Using CO 2 to produce energy, Na–CO 2 battery provides a reliable energy supplement for Mars exploration. [Display omitted] • Solid-state Na–CO 2 battery with inorganic solid-state electrolyte, Na 3 Zr 2 Si 2 PO 12 , has been firstly reported. • The concept of "tri-conductive" cathode, which is ionic, electronic, and gas conductive, has been proposed as the ideal cathode of metal–air battery. • Succinonitrile, a plastic crystal electrolyte, has been employed to build an ionic conductive framework in Ru/CNT to fabricate the "tri-conductive" cathode. • Kinetically stable interphase has been revealed on the anode side of NZSP by theoretical calculation and experiments. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the effects of a smart body tie on the bottom-gate polycrystalline silicon thin film transistor (TFT). The smart body tie TFT has been fabricated and exhibits the superior electrical characteristics, though it involves only a minor modification to the conventional bottom-gate TFT. The results show that the OFF-state leakage of the proposed TFT is reduced by about 70% as compared to a conventional TFT. The drain induced barrier lowing (DIBL) and the subthreshold factor are also improved. The output characteristics are also improved, as the proposed structure does not exhibit a significant kink effect. [Copyright &y& Elsevier]

Abstract: This study investigates structural modifications of the conventional TFT, which is suffers from the short-channel effect in advanced applications. An ideal body-block poly-Si thin-film transistor is successfully fabricated for the first time at a level that achieves high performance characteristics. The output characteristics of the body-block TFT, for instance, the low output conductance in the saturation area and high breakdown voltage, achieve an outstanding improvements compared to a conventional TFT. The poly-Si thin-film treatments of the body-block TFT with NH3 diffusion or body implantation, and their corresponding performance effects, have also been investigated and discussed in depth. [Copyright &y& Elsevier]

• Photocatalyst Water splitting as clear energy for hydrogen evolution reaction. • Silicon earth-abound material as substrate photoabsorber absorbs wide range solar light. • Carbon material low cost, high chemical stability for water splitting. • Graphene synthesis by different methods, next though to transferred to silicon by polymer substrate as a catalyst layer. In the present report, graphene-based catalysts on silicon substrate have been examined as the photocathode for solar hydrogen evolution reaction (HER). Mono-layered graphene has been synthesized through low-pressure chemical vapor deposition (LPCVD), whereas multi-layered graphene has been synthesized by atmospheric pressure chemical vapor deposition (APCVD). Copper foil is used as the substrate. The graphene layer on Cu foil subsequently transferred on to silicon photoabsorber using poly(methyl-2-methylpropenoate) (PMMA). At the initial linear sweep voltammetry (LSV) scan, LPCVD-synthesized graphene-Si (LPCVD-Si) electrode showed an onset potential of −0.65 V and photocurrent of −4.31 mA cm−2 (at −0.385 V). On the contrary, the onset potential and photocurrent of APCVD-prepared graphene-Si (APCVD-Si) photocathode are −0.36 V and −28.28 mA cm−2 (at −0.385 V), respectively. After the 130th LSV scan, the onset potential and photocurrent of LPCVD-Si improved to −0.39 V and −13.28 mA cm−2 (at −0.385 V), respectively. In addition, the onset potential and photocurrent of APCVD-Si photocathode at the LSV 130th scan are enhanced to −0.36 V and −28.28 mA cm−2 (at −0.385 V), respectively. The graphene sample grown via LPCVD-Si show stable performance whereas, the graphene obtained via APCVD-Si have higher photocurrent poor stability. [ABSTRACT FROM AUTHOR]

Na–CO 2 battery is one of the most promising energy storage devices for the exploration of Mar. To fix the evaporation problem of liquid electrolytes in an open system, solid-state electrolyte Na 3 Zr 2 Si 2 PO 12 (NZSP) is used to fabricate a solid-state Na–CO 2 battery. In the battery, the interface between the Na-metal anode and NZSP plays a vital role in improving electrochemical performance. The interfacial parasitic reaction between NZSP and Na-metal results in a Na-rich kinetically stable interphase. (200) and (−111) planes are the preferentially etched crystal planes of NZSP, as SiO 4 and PO 4 tetrahedrons on the planes are easily broken by extra Na-ion injection. Aside from the interfacial reaction, the poor contact between Na-metal and NZSP is a more serious problem, which leads to large interfacial resistance and poor cycling stability. To fix this problem, carbon black is mixed with melted Na-metal to prepare a composite anode (Na@C). The Na@C composite anode easily wets NZSP, thus decreasing the interfacial resistance from 918 to 98 Ω cm2. Symmetrical cells stably cycled 1100 h at 0.1 mA cm−2, when using Na@C as the electrode. Furthermore, Na–CO 2 battery with Na@C composite anode also shows a prolonged cycling life. [Display omitted] ● (200) and (−111) planes are found as preferentially etched crystal planes of NZSP. ● Kinetically stable interphase between Na and NZSP has been found. ● Poor interfacial contact between Na and NZSP results in poor cycling stability. ● Na@C composite anode makes intimate contact with NZSP. ● The solid-state Na–CO 2 battery shows better performance by using Na@C. [ABSTRACT FROM AUTHOR]

A graphene/silicon (Si) multilayer sandwich structures are fabricated using electron beam (EB) deposition without air exposure. The graphene and Si thin films are formed on Cu current correctors through a continuous process in high-vacuum EB chamber. Synthesized graphene should be suggested to the stacked multiple layer from Raman analysis. The fabricated multilayer films are used as anodes. In the beginning, the half-cell, which used a seven-layer of each thickness 50-nm graphene and Si film, exhibits good specific capacity retention over 1000 mA h g −1 after 30 charge/discharge cycles. The capacity value changed with the number of graphene and Si layers. In this study, the number of layers that exhibited optimal properties is seven. Morphological investigation showed a fine layer-by-layer structure. The relationship between different thicknesses of graphene and Si is investigated at 7 L. A 100-nm thickness exhibited optimal properties. Finally, the optimal 7 L and 100-nm thick graphene/Si exhibited high discharge capacitance >1600 mA h g −1 at a current density of 100 mA g −1 after 30 cycles. Initial coulombic and reversible efficiencies exceed 84%. The capacity retention (30th/1st discharge value) at 100 nm and 7 L exceeds 90%. Finally, the soft package battery is assembled by combining the fabricated graphene and Si electrode as anode, LiCoO 2 as cathode, separator and liquid electrolyte. It can be used for commercial light-emitting diode (LED) lighting even under bending status. [ABSTRACT FROM AUTHOR]

Abstract: A new proposed flash memory with divided p-substrate-line (PBL) in modified NOR-type array is described. The programming method of band-to-band tunneling induced substrate hot electron injection (BBISHE) provides high programming efficiency. Realized in NOR-type array and combining with the channel FN ejection erasure, the cell guarantees fast random access capability. The BBISHE programming flash memory features high programming efficiency, low voltage operation, high-speed and reliability up to 104 P/E cycles. [Copyright &y& Elsevier]

Near-infrared (NIR) phosphors are enticing photoluminescent materials with applications in light-emitting diodes for spectroscopy. These phosphors have two types of emissions: Type I has a Gaussian curve, whereas Type II is similar to a plateau. Both emissions have industrial uses, but uncertain remains regarding which type is ideal. In this review, we compare two distinct NIR phosphors with Type I and Type II emissions in terms of their structure, crystal field, and emission profile and then provide our perspective on what the ideal emission must be. Image 1 • Near-infrared phosphors as main components for light-emitting diode devices. • Type-I near-infrared emission has a Gaussian curve with high luminescent intensity. • Type-II near-infrared emission has a plateau shape with superior broadband coverage. • Strategy in order to achieve the ideal emission for near-infrared light-emitting diodes. [ABSTRACT FROM AUTHOR]