Resistive Switching based Electro-Optical Modulation

Cataloged from PDF version of article.Resistive switching enables optical modulation via atomic scale modifications that induce change in the refractive index of active device materials. The formation of filaments and migration of atoms around these filaments between high resistance and low resistance states results in the modulation of the free carrier concentration and, hence, the optical constants of the material

Silicon nanoparticle charge trapping memory cell

Cataloged from PDF version of article.A charge trapping memory with 2 nm silicon nanoparticles (Si NPs) is demonstrated. A zinc oxide (ZnO) active layer is deposited by atomic layer deposition (ALD), preceded by Al2O3 which acts as the gate, blocking and tunneling oxide. Spin coating technique is used to deposit Si NPs across the sample between Al2O3 steps. The Si nanoparticle memory exhibits a threshold voltage (V-t) shift of 2.9 V at a negative programming voltage of -10 V indicating that holes are emitted from channel to charge trapping layer. The negligible measured V-t shift without the nanoparticles and the good retention of charges (> 10 years) with Si NPs confirm that the Si NPs act as deep energy states within the bandgap of the Al2O3 layer. In order to determine the mechanism for hole emission, we study the effect of the electric field across the tunnel oxide on the magnitude and trend of the V-t shift. The Vt shift is only achieved at electric fields above 1 MV/cm. This high field indicates that tunneling is the main mechanism. More specifically, phonon-assisted tunneling (PAT) dominates at electric fields between 1.2 MV/cm 2.1 MV/cm).(C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Possible Single Resonant Production of the Fourth Generation Charged Leptons at γe\gamma e Colliders

Single resonant productions of the fourth standard model generation charged lepton via anomalous interactions at gamma e colliders based on future linear e^+ e^- colliders with 500 GeV and 1 TeV center of mass energies are studied. Signatures of $\gamma e\to \ell_4\to e\gamma$ and $\gamma e\to \ell_4\to eZ$ anomalous processes followed by the hadronic and leptonic decay of the Z boson and corresponding standard model backgrounds are discussed in details. The lowest necessary luminosities to observe these processes and the achievable values of the anomalous coupling strengths are determined.Comment: 9 pages, 6 figures, 4 table

QuaSI: Quantile Sparse Image Prior for Spatio-Temporal Denoising of Retinal OCT Data

Optical coherence tomography (OCT) enables high-resolution and non-invasive 3D imaging of the human retina but is inherently impaired by speckle noise. This paper introduces a spatio-temporal denoising algorithm for OCT data on a B-scan level using a novel quantile sparse image (QuaSI) prior. To remove speckle noise while preserving image structures of diagnostic relevance, we implement our QuaSI prior via median filter regularization coupled with a Huber data fidelity model in a variational approach. For efficient energy minimization, we develop an alternating direction method of multipliers (ADMM) scheme using a linearization of median filtering. Our spatio-temporal method can handle both, denoising of single B-scans and temporally consecutive B-scans, to gain volumetric OCT data with enhanced signal-to-noise ratio. Our algorithm based on 4 B-scans only achieved comparable performance to averaging 13 B-scans and outperformed other current denoising methods.Comment: submitted to MICCAI'1

Electrically controlled resistive switching assisted active ultra-broadband optical tunability in the infrared

We present an electrically tunable optical device with ultra-broadband tunability operating in 2-10 μm spectrum. We also, for the first time, optically observe resistive switching behavior in reflection measurements under electrical bias. © 2013 IEEE

Resistive switching-based electro-optical modulation

[No abstract available

A novel spherical fuzzy AHP method to managing waste from face masks and gloves : an Istanbul-based case study

Waste management has emerged as a critical issue in the wake of the COVID-19 pandemic and the earthquake that struck southeast Turkey on February 6th, 2023, particularly regarding the disposal of face masks and gloves. Extensively utilized for disease prevention and maintaining personal hygiene, these items are categorized as medical waste, presenting significant disposal challenges in Turkey. This study aims to overcome these challenges by prioritizing key factors in waste management during the COVID-19 era through the application of the Spherical Fuzzy Analytic Hierarchy Process (SF-AHP) in Istanbul. By conducting a comprehensive literature review and consulting with experts, relevant criteria for managing this medical waste have been identified and prioritized. Furthermore, a sensitivity analysis of the decision support model is performed to evaluate its robustness. The data highlight the crucial importance of recycling, landfilling, and incineration capacities, regulatory frameworks, and incineration costs as primary determinants and criteria shaping the waste management landscape. The sensitivity analysis highlights the resilience of our proposed methodology, demonstrating consistent and robust prioritization outcomes even with varying criteria weights, thereby validating the reliability of the methodology in informing policy decisions. The originality of this study lies in its innovative application of spherical fuzzy sets—offering high accuracy and compatibility with human reasoning—to the management of face masks and gloves waste, an area not previously explored using Spherical Fuzzy Multi-Criteria Decision Making (SF-MCDM) in current literature. This novel approach introduces a rigorous and pioneering methodology for investigating this specific aspect of waste management and enriches the academic conversation by providing a practical SF-MCDM framework

Plasmonically enhanced ZnO thin-film-photo-transistor with dynamic responsivity control

We fabricated an ZnO based thin-film photo-transistor with electrically tunable photo-responsivity operating in the UV and visible spectra and designed plasmonic structures enhancing the device performance up to 6 folds below the band-gap of ZnO. © 2013 IEEE

Low power zinc-oxide based charge trapping memory with embedded silicon nanoparticles via Poole-Frenkel hole emission

A low power zinc-oxide (ZnO) charge trapping memory with embedded silicon (Si) nanoparticles is demonstrated. The charge trapping layer is formed by spin coating 2 nm silicon nanoparticles between Atomic Layer Deposited ZnO steps. The threshold voltage shift (ΔVt) vs. programming voltage is studied with and without the silicon nanoparticles. Applying -1 V for 5 s at the gate of the memory with nanoparticles results in a ΔVt of 3.4 V, and the memory window can be up to 8 V with an excellent retention characteristic (>10 yr). Without nanoparticles, at -1 V programming voltage, the ΔVt is negligible. In order to get ΔVt of 3.4 V without nanoparticles, programming voltage in excess of 10 V is required. The negative voltage on the gate programs the memory indicating that holes are being trapped in the charge trapping layer. In addition, at 1 V the electric field across the 3.6 nm tunnel oxide is calculated to be 0.36 MV/cm, which is too small for significant tunneling. Moreover, the ΔVt vs. electric field across the tunnel oxide shows square root dependence at low fields (E 1 MV/cm) and a square dependence at higher fields (E > 2.7 MV/cm). This indicates that Poole-Frenkel Effect is the main mechanism for holes emission at low fields and Phonon Assisted Tunneling at higher fields. © 2014 AIP Publishing LLC

2-nm laser-synthesized Si nanoparticles for low-power charge trapping memory devices

In this work, the effect of embedding Silicon Nanoparticles (Si-NPs) in ZnO based charge trapping memory devices is studied. Si-NPs are fabricated by laser ablation of a silicon wafer in deionized water followed by sonication and filtration. The active layer of the memory was deposited by Atomic Layer Deposition (ALD) and spin coating technique was used to deliver the Si-NPs across the sample. The nanoparticles provided a good retention of charges (>10 years) in the memory cells and allowed for a large threshold voltage (Vt) shift (3.4 V) at reduced programming voltages (1 V). The addition of ZnO to the charge trapping media enhanced the electric field across the tunnel oxide and allowed for larger memory window at lower operating voltages. © 2014 IEEE