63 research outputs found

    Disordered Nanohole Patterns in Metal-Insulator Multilayer for Ultra-broadband Light Absorption: Atomic Layer Deposition for Lithography Free Highly repeatable Large Scale Multilayer Growth

    Get PDF
    In this paper, we demonstrate a facile, lithography free, and large scale compatible fabrication route to synthesize an ultra-broadband wide angle perfect absorber based on metal-insulator-metal-insulator (MIMI) stack design. We first conduct a simulation and theoretical modeling approach to study the impact of different geometries in overall stack absorption. Then, a Pt-Al2O3 multilayer is fabricated using a single atomic layer deposition (ALD) step that offers high repeatability and simplicity in the fabrication step. In the best case, we get an absorption bandwidth (BW) of 600 nm covering a range of 400 nm-1000 nm. A substantial improvement in the absorption BW is attained by incorporating a plasmonic design into the middle Pt layer. Our characterization results demonstrate that the best configuration can have absorption over 0.9 covering a wavelength span of 400 nm-1490 nm with a BW that is 1.8 times broader compared to that of planar design. On the other side, the proposed structure retains its absorption high at angles as wide as 70°. The results presented here can serve as a beacon for future performance enhanced multilayer designs where a simple fabrication step can boost the overall device response without changing its overall thickness and fabrication simplicity. © 2017 The Author(s)

    Flexible and fragmentable tandem photosensitive nanocrystal skins

    Get PDF
    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the currentmatching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm⁻² at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion

    Ultra-broadband, wide angle absorber utilizing metal insulator multilayers stack with a multi-thickness metal surface texture

    Get PDF
    In this paper, we propose a facile route to fabricate a metal insulator multilayer stack to obtain ultra-broadband, wide angle behavior from the structure. The absorber, which covers near infrared (NIR) and visible (Vis) ranges, consists of a metal-insulator-metal-insulator (MIMI) multilayer where the middle metal layer has a variant thickness. It is found that this non-uniform thickness of the metal provides us with an absorption that is much broader compared to planar architecture. In the non-uniform case, each thickness is responsible for a specific wavelength range where the overall absorption is the superposition of these resonant responses and consequently a broad, perfect light absorption is attained. We first numerically examine the impact of different geometries on the overall light absorption property of the multilayer design. Afterward, we fabricate the designs and characterize them to experimentally verify our numerical findings. Characterizations show a good agreement with numerical results where the optimum absorption bandwidth for planar design is found to be 620 nm (380 nm-1000 nm) and it is significantly boosted to an amount of 1060 nm (350 nm-1410 nm) for multi-thickness case. © 2017 The Author(s)

    Multiexciton generation assisted highly photosensitive CdHgTe nanocrystal skins

    Get PDF
    Multiexciton Generation (MEG) enabled by the photogeneration of more than one electron-hole pairs upon the absorption of a single photon observed in colloidal semiconductor nanocrystals (NCs) is an essential key to high efficiency when operating in large enough photon energy regimes. Here, we report a newly designed class of solution-processed highly sensitive MEG-assisted photosensors of CdHgTe NCs, in which the charge accumulation is dramatically enhanced for photon energies greater than two times the bandgap of the employed NCs. We fabricated and comparatively studied five types of devices based on different NC monolayers of selected quantum-confined bandgaps resulting in different levels of photovoltage buildup readouts. Among these photosensitive platforms, MEG is distinctly observed for CdHgTe NCs, as the number of electrons trapped inside these NCs and the number of holes accumulating into the interfacing metal electrode were increased beyond a single exciton per absorbed photon. Furthermore, we conducted time-resolved fluorescence measurements and confirmed the occurrence of MEG in the CdHgTe NC monolayer of the photosensor. These findings pave the way for engineering of multiexciton kinetics in high-efficiency NC-based photosensors and photovoltaics. © 2016 Elsevier Ltd

    New records and noteworthy data of plants, algae and fungi in SE Europe and adjacent regions, 13

    Get PDF
    This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: brown alga Heribaudiella fluviatilis, red alga Batrachospermum skujae, saprotrophic fungus Gnomonia geranii-macrorrhizi, mycorrhizal fungi Amanita alseides and Russula griseascens, liverwort Ricciocarpos natans, moss Blindia acuta, Leucodon sciuroides var. morensis and Pseudostereodon procerrimus, monocots Allium ampeloprasum, Carex ferruginea and Carex limosa and dicots Convolvulus althaeoides, Fumana aciphylla, Hieracium petrovae, Lamium bifidum subsp. bifidum and Ranunculus fontanus are given within SE Europe and adjacent region

    Trend removal of ECG Signal with LMS algorithm

    No full text
    2019 Medical Technologies Congress, TIPTEKNO 2019 --3 October 2019 through 5 October 2019 -- --In this study, the LMS algorithm was employed to detect and track baseline wanders introduced during the acquisition of electrocardiogram signals. The baseline wander was removed from the signal and ECG is corrected. For this purpose, the baseline signal was modeled as a constant and a line in the LMS algorithm. The two approaches were applied to the signals received from MIB-BIH database records and the results were reported and compared. When the experimental results are investigated it is observed that the line model adapts faster and tracks baseline wander. © 2019 IEEE

    Pharmacogenetics [Farmakogenetik]

    No full text
    Promising investigations are being done in the field of pharmacogenetics in order to link altered drug response to heredity and ultimately determine individually tailored drug therapy (i.e. proper drug, dose and treatment strategy) for each patient. Personal differences in response to therapeutic agents and drug toxicity are quite common in clinical practice. For example, 30% of the schizophrenic patients treated with antipsychotic drugs and 35% of the heart patients receiving ß-blockers do not respond to the therapy at all. On the other hand, only one third of the multiple sclerosis patients respond to interferon treatment. Although, multiple factors including lifestyle, diet, and environment change drug response, the key determinants are genetic differences or polymorphisms among individuals. Polymorphic genes encoding drug metabolizing enzymes, transporters, receptors and other drug targets have been found to influence the therapeutic effectiveness and toxicity of many drugs available in medicine. Therefore, the main objective of pharmacogenetics is to develop concepts in order to maximize drug's efficiency while significantly minimizing its adverse reactions based on predetermined interindividual genetic differences

    infrapopliteal arteries

    No full text
    Objectives To evaluate 36-month outcomes of drug-eluting balloons in infrapopliteal (=below-the-knee) arterial segments, we made a prospective registry enrolling patients (Rutherford class 2 to 5, ankle-brachial index 0.4-0.7) who were revascularized with drug-eluting balloon from August 2011 to December 2014.Methods Three hundred and seven infrapopliteal arteries were revascularized only with drug-eluting balloon. Endpoints included target lesion revascularization, primary patency rate, and changes in ankle-brachial index and Rutherford class.Results Both ankle-brachial index improvement and Rutherford reduction were statistically significant (p<0.001). At 36 months control, ankle-brachial index improvement was 59.3% (p=0.032). The clinically driven target lesion revascularization rate was 28% at 36 months. Limb salvage was accomplished in 73.6% of the critical limb ischemia cases, and complete wound healing was detected in 67.8% of cases with Rutherford category 5. Overall, the 1-year primary patency rate was 32.5%.Conclusions Drug-eluting balloons have shown successful performance in infrapopliteal arteries in mid-term, and evidence regarding clinical effectiveness and safety supports drug-eluting balloon angioplasty as the first line therapy in this segment

    Thirty-six-month outcomes of drug-eluting balloon angioplasty in the infrapopliteal arteries

    No full text
    Objectives: To evaluate 36-month outcomes of drug-eluting balloons in infrapopliteal (=below-the-knee) arterial segments, we made a prospective registry enrolling patients (Rutherford class 2 to 5, ankle–brachial index 0.4–0.7) who were revascularized with drug-eluting balloon from August 2011 to December 2014. Methods: Three hundred and seven infrapopliteal arteries were revascularized only with drug-eluting balloon. Endpoints included target lesion revascularization, primary patency rate, and changes in ankle–brachial index and Rutherford class. Results: Both ankle–brachial index improvement and Rutherford reduction were statistically significant (p < 0.001). At 36 months control, ankle–brachial index improvement was 59.3% (p = 0.032). The clinically driven target lesion revascularization rate was 28% at 36 months. Limb salvage was accomplished in 73.6% of the critical limb ischemia cases, and complete wound healing was detected in 67.8% of cases with Rutherford category 5. Overall, the 1-year primary patency rate was 32.5%. Conclusions: Drug-eluting balloons have shown successful performance in infrapopliteal arteries in mid-term, and evidence regarding clinical effectiveness and safety supports drug-eluting balloon angioplasty as the first line therapy in this segment. © The Author(s) 2018
    corecore