scholarly journals Fluorine-programmed nanozipping to tailored nanographenes on rutile TiO2 surfaces

Science ◽  
2019 ◽  
Vol 363 (6422) ◽  
pp. 57-60 ◽  
Author(s):  
M. Kolmer ◽  
R. Zuzak ◽  
A. K. Steiner ◽  
L. Zajac ◽  
M. Engelund ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Hydrogen Fluoride ◽  
High Efficiency ◽  
Bond Activation ◽  
Metal Oxide Surfaces ◽  
Titania Surface ◽  
Precursor Structure ◽  
Versatile Tool ◽  
Long Time ◽  
Rutile Titania

The rational synthesis of nanographenes and carbon nanoribbons directly on nonmetallic surfaces has been an elusive goal for a long time. We report that activation of the carbon (C)–fluorine (F) bond is a reliable and versatile tool enabling intramolecular aryl-aryl coupling directly on metal oxide surfaces. A challenging multistep transformation enabled by C–F bond activation led to a dominolike coupling that yielded tailored nanographenes directly on the rutile titania surface. Because of efficient regioselective zipping, we obtained the target nanographenes from flexible precursors. Fluorine positions in the precursor structure unambiguously dictated the running of the “zipping program,” resulting in the rolling up of oligophenylene chains. The high efficiency of the hydrogen fluoride zipping makes our approach attractive for the rational synthesis of nanographenes and nanoribbons directly on insulating and semiconducting surfaces.

Alkane activation on crystalline metal oxide surfaces

2014 ◽  
Vol 43 (22) ◽  
pp. 7536-7547 ◽  
Author(s):  
Jason F. Weaver ◽  
Can Hakanoglu ◽  
Abbin Antony ◽  
Aravind Asthagiri
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Bond Activation ◽  
Oxide Surfaces ◽  
Late Transition Metal ◽  
Alkane Activation ◽  
Metal Oxide Surfaces ◽  
Metal Atoms ◽  
Late Transition ◽  
Crystalline Metal

Late transition-metal oxide surfaces that expose coordinatively-unsaturated metal atoms promote the formation and bond activation of alkane σ-complexes.

scholarly journals Conversion of Methanol on Rutile TiO2 (110) and Tungsten Oxide Clusters: 2. The Role of Defects and Electron Transfer in Bifunctional Oxidic Photocatalysts

2021 ◽  
Author(s):  
Lars Mohrhusen ◽  
Jessica Kräuter ◽  
Katharina Al-Shamery
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Metal Oxide ◽  
Tungsten Oxide ◽  
Organic Compounds ◽  
Uv Irradiation ◽  
Organic P ◽  
Rutile Tio2 ◽  
Metal Oxide Surfaces

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...

scholarly journals Novel semi-analytical optoelectronic modeling based on homogenization theory for realistic plasmonic polymer solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zahra Arefinia ◽  
Dip Prakash Samajdar
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Analytical Modeling ◽  
High Efficiency ◽  
Polymer Solar Cells ◽  
Scattered Light ◽  
Homogenization Theory ◽  
Computational Time ◽  
Coupled Equations ◽  
Long Time

AbstractNumerical-based simulations of plasmonic polymer solar cells (PSCs) incorporating a disordered array of non-uniform sized plasmonic nanoparticles (NPs) impose a prohibitively long-time and complex computational demand. To surmount this limitation, we present a novel semi-analytical modeling, which dramatically reduces computational time and resource consumption and yet is acceptably accurate. For this purpose, the optical modeling of active layer-incorporated plasmonic metal NPs, which is described by a homogenization theory based on a modified Maxwell–Garnett-Mie theory, is inputted in the electrical modeling based on the coupled equations of Poisson, continuity, and drift–diffusion. Besides, our modeling considers the effects of absorption in the non-active layers, interference induced by electrodes, and scattered light escaping from the PSC. The modeling results satisfactorily reproduce a series of experimental data for photovoltaic parameters of plasmonic PSCs, demonstrating the validity of our modeling approach. According to this, we implement the semi-analytical modeling to propose a new high-efficiency plasmonic PSC based on the PM6:Y6 PSC, having the highest reported power conversion efficiency (PCE) to date. The results show that the incorporation of plasmonic NPs into PM6:Y6 active layer leads to the PCE over 18%.

scholarly journals On Performance of Sparse Fast Fourier Transform Algorithms Using the Aliasing Filter

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1117
Author(s):  
Bin Li ◽  
Zhikang Jiang ◽  
Jie Chen
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
High Efficiency ◽  
Theory And Practice ◽  
Long Time ◽  
And Performance ◽  
Binary Tree Search ◽  
The One ◽  
Sparse Fast Fourier Transform ◽  
L1 And L2

Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In order to use them properly, the urgent topic of great concern is how to analyze and evaluate the performance of these algorithms in theory and practice. This paper mainly discusses the technology and performance of sFFT algorithms using the aliasing filter. In the first part, the paper introduces the three frameworks: the one-shot framework based on the compressed sensing (CS) solver, the peeling framework based on the bipartite graph and the iterative framework based on the binary tree search. Then, we obtain the conclusion of the performance of six corresponding algorithms: the sFFT-DT1.0, sFFT-DT2.0, sFFT-DT3.0, FFAST, R-FFAST, and DSFFT algorithms in theory. In the second part, we make two categories of experiments for computing the signals of different SNRs, different lengths, and different sparsities by a standard testing platform and record the run time, the percentage of the signal sampled, and the L0, L1, and L2 errors both in the exactly sparse case and the general sparse case. The results of these performance analyses are our guide to optimize these algorithms and use them selectively.

Geometry-based, n-type-enhanced p-type polymer/metal oxide nanocomposites for high-efficiency, high-specificity conductive systems

2014 ◽  
Vol 1630 ◽  
Author(s):  
Riccardo Raccis ◽  
Laura Wortmann ◽  
Shaista Ilyas ◽  
Johannes Schläfer ◽  
Andreas Mettenbörger ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Percolation Threshold ◽  
High Efficiency ◽  
High Specificity ◽  
Data Fitting ◽  
Basic Properties ◽  
Frenkel Effect ◽  
Polymer Metal ◽  
Different Shapes ◽  
P Type

ABSTRACTHematite (α-Fe2O3) nanoparticles were diffused of two different shapes (spherical and cubical) in PEDOT:PSS matrices below the percolation threshold. Increases in conductivity within a distinct range in concentration were observed in the dark and under simulated solar illumination. The effect was ascribed to a generalized Poole-Frenkel effect in conjunction with basic properties of heterojunctions and electrostatic dipoles, and verified through data fitting. A difference in behaviour between sphere- and cube-based nanocomposites was also observed.

scholarly journals Aqueous Solvation Dynamics at Metal Oxide Surfaces

2006 ◽  
Vol 110 (15) ◽  
pp. 7835-7844 ◽  
Author(s):  
Erwin Portuondo-Campa ◽  
Andreas Tortschanoff ◽  
Frank van Mourik ◽  
Jacques-Edouard Moser ◽  
Andreas Kornherr ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxide Surfaces ◽  
Solvation Dynamics ◽  
Metal Oxide Surfaces ◽  
Aqueous Solvation

A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays

2014 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee
Keyword(s):  
Reverse Bias ◽  
High Efficiency ◽  
Life Time ◽  
Density Currents ◽  
High Brightness ◽  
Light Emitting ◽  
Wide Viewing Angle ◽  
Time Operation ◽  
Long Time ◽  
History Of

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.

scholarly journals Investigation of Water Adsorption on Metal Oxide Surfaces under Conditions Representative of PuO2 Storage Containers

2013 ◽  
Vol 53 (21) ◽  
pp. 81-94 ◽  
Author(s):  
P. M. Murphy ◽  
C. Boxall ◽  
R. J. Taylor ◽  
D. A. Woodhead
Keyword(s):  
Metal Oxide ◽  
Water Adsorption ◽  
Oxide Surfaces ◽  
Metal Oxide Surfaces ◽  
Storage Containers
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