The transition to solid-state Li-ion batteries will enable progress toward energy densities of 1000 W·hour/liter and beyond. Composites of a mesoporous oxide matrix filled with nonvolatile ionic liquid electrolyte fillers have been explored as a solid electrolyte option. However, the simple confinement of electrolyte solutions inside nanometersized pores leads to lower ion conductivity as viscosity increases. Here, we demonstrate that the Li-ion conductivity of nanocomposites consisting of a mesoporous silica monolith with an ionic liquid electrolyte filler can be several times higher than that of the pure ionic liquid electrolyte through the introduction of an interfacial ice layer. Strong adsorption and ordering of the ionic liquid molecules render them immobile and solid-like as for the interfacial ice layer itself. The dipole over the adsorbate mesophase layer results in solvation of the Li + ions for enhanced conduction. The demonstrated principle of ion conduction enhancement can be applied to different ion systems. Mees, P. M. Vereecken, Silica gel solid nanocomposite electrolytes with interfacial conductivity promotion exceeding the bulk Li-ion conductivity of the ionic liquid electrolyte filler. Sci. Adv. 6, eaav3400 (2020).
Arsenic (As + 150 keV, 1.0 × 10 13 cm −2 ) implanted p − -Si(100) wafers were spike annealed at 1100 • C for 1s in a commercially available rapid thermal annealing (RTA) system. Significant variations in sheet resistance were observed while As dopant profiles, measured by secondary ion mass spectroscopy (SIMS), were almost identical. Photoluminescence (PL) spectra were measured from all wafers under three different excitation wavelengths (532, 650 and 827 nm) at room temperature. PL spectra showed large intensity variation, corresponding to the sheet resistance. PL excitation wavelength dependence suggests the variation in density of residual damage as the possible cause of sheet resistance variation. Charge coupled devices (CCDs) have been widely used in scientific instruments and digital cameras until recently.1 The gate structure used in CCDs to transfer electrical charges (image data) to the edge of the sensor, requires a separate power source (more power) and sequential data transfer (slower speed). 2,3For portable device applications, smaller devices with low power consumption are strongly desired. Complementary metal-oxidesemiconductor (CMOS) image sensors, with reduced power consumption and fast data transfer, have become a common alternative choice for image sensors.3 These devices consist of large arrays of photodiodes and amplifiers. The photodiodes accumulate electrical charge and increase voltage when exposed to light. The voltage is amplified and transmitted as electrical signals. Since the CMOS image sensors have the same basic structure as CMOS memory devices, they are cost effectively mass produced, using well-established manufacturing technology. 1Generally, CMOS image sensors generate more electrical noise than CCDs and can result in poor image quality due to performance fluctuations in the large array of photodiodes and amplifiers.3 Small performance differences in photodiodes and amplifiers can result in noise in the output image. The noise problem increases as cell size is reduced and the number of cells in a chip increases. Noise reduction approaches commonly used to overcome this problem are; improved device level performance variation and reduction of the variation of background noise. Device-level noise reduction efforts are also becoming increasingly important. 4 High energy, low dose ion implant conditions are often used in CMOS image sensor fabrication processes. Average dopant concentration in the implanted junctions are 2 ∼ 3 orders of magnitude lower than those of advanced CMOS logic and memory devices. Small amounts of defects and residual damage have a significant impact in the electrical properties of implanted junctions after RTA. To reduce noise in CMOS image sensors, elimination of defects and residual damage are very important steps. The room temperature photoluminescence (RTPL) technique can be used for finding and reducing the electrically active and/or non-radiative defects and damage in the early stage of CMOS image sensor fabrication steps.It is well known that metal c...
A nanocomposite electrolyte composed of a non-volatile ionic liquid, organic Li-salt and porous-inorganic material can be a promising option as a solid electrolyte material. We present a high-rate performance in solid-state lithium metal and Li-ion batteries using a silica-gel solid nanocomposite electrolyte (nano-SCE) made by the sol-gel method with a bis(fluorosulfonyl)imide (FSI)-based ionic liquid. The nano-SCE, composed of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl) imide (EMI-FSI) and Li-FSI confined in the mesoporous silica matrix, exhibits an ionic conductivity of 6.2 mS cm−1 at room temperature. The capacity of the Li-LiFePO4 cell using the EMI-FSI based nano-SCE reaches 150 mAh g−1 at 0.1C and 113 mAh g−1 at 1C, which is higher than that achieved by the other reported batteries that use a similar composite electrolyte. The C-rate performance of the prepared solid batteries is comparable to that of cells with the conventional lithium hexafluorophosphate (LiPF6) electrolyte. Our results show that impregnation of a liquid precursor is an efficient approach for an excellent electrode/electrolyte interface contact in the solid composite electrode as the reaction kinetics at the interface of the active mass and nano-SCE are sufficiently fast, and thus is advantageous compared with the other types of solid electrolytes.
PACS 76.70.Fz Dynamic nuclear polarization of the 29Si nuclei due to the "solid-effect" was observed clearly after saturation of the phosphorus electron paramagnetic resonance lines in three kinds of silicon crystals containing different amount of the 29 Si isotope (1 %, 4.7 %, and 99.3 %). Maximal enhancement (E) of the roomtemperature . It has been shown that in silicon containing phosphorus atoms at the concentrations lower than 5×10 16 cm -3 the dominant mechanism of DNP is so called "solid-effect" [1-3]. This mechanism is realized under saturation of the forbidden "flip-flop" and "flip-flip" transitions in the dipole-dipole coupled electron nuclear system [2,3]. The enhancement of the nuclear polarization E = P N /P N0 = 30, where P N is the DNP degree and P N0 is the equilibrium nuclear polarization, was obtained at 4.2 K under saturation of the forbidden transitions by microwave field at the frequency of 9 GHz [1]. The observed enhancement E is significantly lower than the maximal theoretical value E m = (γ e /γ N ) =3310, where γ e and γ N are electron and 29 Si nuclear gyromagnetic ratios, respectively. The low value of E can be explained by two factors. First, the long electron spin relaxation time T e ≈ 1 -10 s [4] of electrons localized at phosphorus atoms at 4.2 K reduces the value of E by factor 1/(1+ f) [3] where f = NT e /nT
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