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This letter presents a feasible and cost‐effective approach to realize closed laminated core, which is used to realize on silicon integrated thin film inductors. The closed laminated core is fabricated by electroplating magnetic layers with an oxide insulation layer sputtered in‐between. This is compatible with the back end of line (BEOL) processes. The prototype of the thin film inductor with closed laminated core shows less degradation of AC inductance and smaller AC resistance at high frequencies than the variant with a solid core. Furthermore, it is tested in a 20‐MHz DC–DC converter. The peak efficiency of 80% was achieved. [ABSTRACT FROM AUTHOR]

This letter demonstrates an on-silicon integrated thin film coupled inductor using a novel cascade matrix concept to suit multiphase integrated voltage regulator (IVR) applications. The novel cascade matrix coupled (CMC) stripline inductor facilitates all-phase-coupled configuration to reduce the phase ripple current in IVRs. It also shows excellent scalability and neat floor planning. Moreover, the proposed CMC inductor uses double layer metal scheme for windings and interconnects, which significantly reduces the ac winding resistance. A four-phase CMC inductor has been successfully fabricated on-silicon substrate and characterized, which uses conventional thin film magnetic core deposition process to achieve in-plane magnetic uniaxial anisotropy. The device occupies 3.2 × 1.7 mm2 floor area and provides 19.5 nH phase inductance with 120 mΩ dc resistance. The saturation current for each phase is up to 0.4 A when the phase inductance drops by approximately 20%. The coupling coefficient between any two phases of the proposed CMC inductor is 0.27, much higher and more controllable than that of toroid core-based coupled inductors. [ABSTRACT FROM AUTHOR]

Thin-film Si-integrated inductors with closed cores have different magnetic field distributions in the winding window space compared to the inductors with unclosed cores. One-dimensional methods are no longer applicable for these inductors to calculate the ac resistance. Based on the analysis of the magnetic field distribution of the devices, a 2-D field solution was developed, which leads to an improved 2-D method to calculate the ac resistance of the device. High accuracy of this new approach has been verified by finite-element analysis, while 1-D methods can lead to significant errors. [ABSTRACT FROM AUTHOR]

Abstract: Micro-inductors, with an electrodeposited nickel–iron core have been fabricated on silicon substrates, and have been characterized in the frequency range up to 100MHz. The core consists of a nickel iron, 45:55 alloy which is deposited using pulse-reverse electroplating in the presence of a magnetic field to control anisotropy. The operation of the inductors with low loss at high-frequency critically depends on core thickness, which is used to control eddy-current loss as the frequency is increased. However, it is shown that the permeability of NiFe 45/55 has a dependency on thickness, and decreases with increasing thickness. For example, the permeability is measured to be approximately 1000 for a 1-μm-thick film, decreasing to approximately 400 for a 5-μm-thick film. In order to correctly design micro-inductors for operation up to 100MHz, it is important that this characteristic of the material is taken into account. [Copyright &y& Elsevier]

Localized surface plasmon resonances in metallic nanostructures have been extensively harnessed for light absorption enhancement in various solar cells, including perovskite solar cells (PSCs). For stabilization and functionalization, plasmonic metal nanostructures are often coated with dielectric shells. In this work, we numerically investigate the effects of dielectric coated plasmonic metal nanoparticles (NPs) on solar absorption enhancement in perovskite thin films. To our surprise, a further absorption enhancement compared with the films embedding bare Ag NPs can be achieved when using thin dielectric coating of high refractive index, while an absorption reduction in comparison with bare perovskite thin films may take place when the embedded Ag NPs are coated with thick dielectric shells of low refractive index. The physics behind is addressed within classic electrodynamics. These anomalous effects extend our knowledge of PSCs, providing guidelines for optimized design of plasmonic solar cells. [ABSTRACT FROM AUTHOR]

In an integrated power microinductor, the size and shape of the magnetic material will have a relationship to the permeability and inductance of the device. To demonstrate these effects, a set of inductors with closed Ni45Fe55 films were fabricated having similar structures but different footprint sizes and aspect ratios (ARs). Magnetic and electrical characterization was performed on the devices to determine magnetic properties, and in both measurements the same relationship between film shape and magnetic anisotropy is observed. Micromagnetic shape anisotropy simulations were used to predict this behavior and correlate with the experimentally determined parameters. The AR of the film is determined to have a strong influence on the anisotropy and permeability of the magnetic film via shape demagnetization effects which is shown to be a significant variation from the as-deposited magnetic material parameters. [ABSTRACT FROM AUTHOR]

ABSTRACT Two alternating medium band gap conjugated polymers (PBDT-TPTI and PDTBDT-TPTI) derived from 4,8-bis(4,5-dioctylthien-2-yl)benzo[1,2- b:4,5- b′]dithiophene (BDT-T) or 5,10-bis(4,5-didecylthien-2-yl)dithieno[2,3- d:2′,3′- d′]benzo[1,2- b:4,5- b′]dithiophene (DTBDT-T) with pentacyclic aromatic lactam of N, N-didodecylthieno[2′,3′:5,6]pyrido[3,4- g]thieno[3,2- c]- iso-quinoline-5,11-dione (TPTI), are synthesized and characterized. The comparative investigation of the photostabilities of the copolymers revealed that the PDTBDT-TPTI film exhibited the comparable photostability in relative to P3HT. Meanwhile, the inverted photovoltaic cells ( i-PVCs) from the blend films of PBDT-TPTI and/or PDTBDT-TPTI with PC71BM, in which poly[(9,9-bis(3′-( N, N-dimethylamino)propyl)-2,7-fluorene)- alt-2,7-(9,9-dioctylfluorene)] were used as cathode modifying interlayer, presented higher power conversion efficiencies (PCEs) of 5.98% and 6.05% with photocurrent response ranging from 300 nm to 650 nm in contrast with the PCEs of 4.48% for the optimal inverted PVCs from P3HT/PC71BM under AM 1.5 G 100 mW/cm2. The PCEs of the i-PVCs from PBDT-TPTI and PDTBDT-TPTI were improved to 7.58% and 6.91% in contrast to that of 0.02% for the P3HT-based i-PVCs, and the photocurrent responses of the devices were extended to 300-792 nm, when the ITIC was used as electron acceptor materials. The results indicate that the PBDT-TPTI and PDTBDT-TPTI can be used as the promising alternatives of notable P3HT in the photovoltaic application. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 85-95 [ABSTRACT FROM AUTHOR]

Dispersion state of inorganic nanoparticles (NPs) in the composite films may significantly influence on the film properties. In the present study, polymer/SiO 2 nanocomposite particles (NCPs) with various SiO 2 grafting states (various grafting ratios, various linking patterns between SiO 2 NPs, and various types of grafted chains), were prepared through in situ emulsion or in situ miniemulsion technique. These NCPs were used as building blocks to prepare composite films. The microscopic observations and surface composition analyses of the composite films manifest that the spatial distribution of SiO 2 NPs in the composite films depends on the baking temperature, SiO 2 grafting state, and the compatibility between SiO 2 NPs and polymer matrix. The SiO 2 NPs might display a cluster-like distribution, homogenous one, or locally aggregated one. The results from this study demonstrate how the grafting state of inorganic NPs is effective in controlling dispersion state of inorganic NPs and further determining the properties of composite films. [ABSTRACT FROM AUTHOR]

9,11,12,14-Tetraaryldibenzo[ f, h]imidazo[1,2- b]isoquinolines 3a- h were synthesized in moderate yields through the reaction of benzils with 1,3-diphenyl-2 H-cyclopenta[ l]phenanthren-2-ones and ammonium acetate. The photophysical properties of the products in solutions and in thin films were investigated, and strong emissions ranging from 492 to 516 nm were observed in cyclohexane solutions. Moreover, 3h exhibited potential as a versatile fluorescent chemosensor for the detection of solvent polarity, acidity, or trace amounts of nitroaromatics. [ABSTRACT FROM AUTHOR]

• A micro-inductor has been fabricated using a MEMS process. • The device has a single layer copper winding sandwiched between two layers of core. • The micro-inductor has a footprint area of 2.9 mm2. • The measured inductance is 204 nH at 21.7 MHz and DC resistance is 470 m Ω. • The peak quality factor of the micro-inductor is 9.23 at 9.2 MHz. • The micro-inductor has been applied in a buck converter. • The achieved maximum converter efficiency is 81.74% at 20 MHz. • The micro-inductor has also been compared with an air core inductor embedded in PCB. • The 220 nH air core inductor has a large footprint area of 32 mm2. • The maximum converter efficiency is 85.47% when the air core inductor is applied. A micro-inductor has been fabricated on silicon substrate using a Micro-Electromechanical Systems (MEMS) process. The micro-inductor has a single layer copper winding sandwiched between two layers of electroplated NiFe core. It has a footprint area of 2.9 mm2, an inductance of 204 nH at 21.7 MHz, a DC resistance of 470 m Ω , and a peak quality factor of 9.23 at 9.2 MHz. The micro-inductor has been applied in a buck converter and achieved a maximum converter efficiency of 81.74% at 20 MHz. The performance of the micro-inductor has also been compared with an air-core inductor embedded in PCB. The air core inductor has a similar inductance of 220 nH, but with a large footprint area of 32 mm2. The maximum buck converter efficiency is 85.47% when the air core inductor is applied. [ABSTRACT FROM AUTHOR]