scholarly journals Giant exciton-enhanced shift currents and direct current conduction with subbandgap photo excitations produced by many-electron interactions

2021 ◽  
Vol 118 (25) ◽  
pp. e1906938118
Author(s):  
Yang-Hao Chan ◽  
Diana Y. Qiu ◽  
Felipe H. da Jornada ◽  
Steven G. Louie
Keyword(s):  
Direct Current ◽  
Continuous Wave ◽  
Building Blocks ◽  
Next Generation ◽  
Photovoltaic Devices ◽  
Electron Hole ◽  
Two Dimensional Materials ◽  
Light Matter Interaction ◽  
Time Propagation ◽  
Current Shift

Shift current is a direct current generated from nonlinear light–matter interaction in a noncentrosymmetric crystal and is considered a promising candidate for next-generation photovoltaic devices. The mechanism for shift currents in real materials is, however, still not well understood, especially if electron–hole interactions are included. Here, we employ a first-principles interacting Green’s-function approach on the Keldysh contour with real-time propagation to study photocurrents generated by nonlinear optical processes under continuous wave illumination in real materials. We demonstrate a strong direct current shift current at subbandgap excitation frequencies in monolayer GeS due to strongly bound excitons, as well as a giant excitonic enhancement in the shift current coefficients at above bandgap photon frequencies. Our results suggest that atomically thin two-dimensional materials may be promising building blocks for next-generation shift current devices.

scholarly journals Recent Progress in the Synthesis and Characterization of Diarylethene-based MOFs

2014 ◽  
Vol 70 (a1) ◽  
pp. C1223-C1223
Author(s):  
Jason Benedict ◽  
Ian Walton ◽  
Dan Patel ◽  
Jordan Cox
Keyword(s):  
Chemical Properties ◽  
Building Blocks ◽  
Synthesis And Characterization ◽  
Next Generation ◽  
Design Synthesis ◽  
Thermally Induced ◽  
Potential Applications ◽  
External Stimuli ◽  
Physical And Chemical

Metal-organic Frameworks (MOFs) remain an extremely active area of research given the wide variety of potential applications and the enormous diversity of structures that can be created from their constituent building blocks. While MOFs are typically employed as passive materials, next-generation materials will exhibit structural and/or electronic changes in response to applied external stimuli including light, charge, and pH. Herein we present recent results in which advanced photochromic diarylethenes are combined with MOFs through covalent and non-covalent methods to create photo-responsive permanently porous crystalline materials. This presentation will describe the design, synthesis, and characterization of next-generation photo-switchable diarylethene based ligands which are subsequently used to photo-responsive MOFs. These UBMOF crystals are, by design, isostructural with previously reported non-photoresponsive frameworks which enables a systematic comparison of their physical and chemical properties. While the photoswitching of the isolated ligand in solution is fully reversible, the cycloreversion reaction is suppressed in the UBMOF single crystalline phase. Spectroscopic evidence for thermally induced cycloreversion will be presented, as well as a detailed analysis addressing the limits of X-ray diffraction techniques applied to these systems.

scholarly journals Biphasic direct current shift, haemoglobin desaturation and neurovascular uncoupling in cortical spreading depression

Brain ◽  
2010 ◽  
Vol 133 (4) ◽  
pp. 996-1012 ◽  
Author(s):  
Joshua C. Chang ◽  
Lydia L. Shook ◽  
Jonathan Biag ◽  
Elaine N. Nguyen ◽  
Arthur W. Toga ◽  
...  
Keyword(s):  
Direct Current ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Current Shift

scholarly journals Solution-processed two-dimensional materials for next-generation photovoltaics

2021 ◽  
Author(s):  
Sebastiano Bellani ◽  
Antonino Bartolotta ◽  
Antonio Agresti ◽  
Giuseppe Calogero ◽  
Giulia Grancini ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Next Generation ◽  
Solution Processed ◽  
Two Dimensional Materials

Solution-processed graphene and related two-dimensional materials enable the next-generation photovoltaics.

Research trends of MXenes as the Next-generation Two-dimensional Materials

2021 ◽  
Vol 28 (2) ◽  
pp. 150-163
Author(s):  
Hojun Lee ◽  
◽  
Yejun Yun ◽  
Jinkwang Jang ◽  
Jongmin Byun
Keyword(s):  
Research Trends ◽  
Two Dimensional ◽  
Next Generation ◽  
Two Dimensional Materials

scholarly journals Next generation polymeric high voltage direct current cables—A quantum leap needed?

2018 ◽  
Vol 34 (2) ◽  
pp. 24-31 ◽  
Author(s):  
Gian Carlo Montanari ◽  
Paolo Seri ◽  
Xianzhang Lei ◽  
Hanyu Ye ◽  
Qikai Zhuang ◽  
...  
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Next Generation ◽  
High Voltage Direct Current ◽  
Quantum Leap

Two-dimensional materials for next-generation computing technologies

2020 ◽  
Vol 15 (7) ◽  
pp. 545-557 ◽  
Author(s):  
Chunsen Liu ◽  
Huawei Chen ◽  
Shuiyuan Wang ◽  
Qi Liu ◽  
Yu-Gang Jiang ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Next Generation ◽  
Computing Technologies ◽  
Generation Computing ◽  
Two Dimensional Materials

scholarly journals Bitstream radar waveforms for generic single-chip radar

2017 ◽  
Vol 9 (6) ◽  
pp. 1325-1337
Author(s):  
Øystein Bjørndal ◽  
Svein-Erik Hamran ◽  
Tor Sverre Lande
Keyword(s):  
Continuous Wave ◽  
Random Noise ◽  
Building Blocks ◽  
Single Chip ◽  
Waveform Generator ◽  
Digital Signals ◽  
Xor Gate ◽  
Amplitude Resolution ◽  
Radar Waveforms ◽  
Noise Sequence

Bitstreams, square wave digital signals, enable flexible radar implementations in modern digital technology. By using bitstreams in place of analog sinusoidal waveforms, we can realize continuous-wave (CW), stepped-frequency CW, frequency-modulated CW, or even pseudo random noise-sequence and pulsed radars, all with a single bit of amplitude resolution. The building blocks are a programable waveform generator, a sweep threshold quantizer, digital delay, and a digital XOR gate as a mixer. This gives us a novel, almost fully digital (requiring only a comparator) system, as previously proposed and which is extended here. The flexibility of the transmitter allows for easy switching between waveforms and the bitstream signal can be processed with single-bit digital gates. Single-bit signals allows for exploration of novel continuous time non-clocked digital implementations to maximize speed and energy efficiency. Mixing frequencies with a digital XOR gate creates harmonics, which are explored for multiple solutions utilizing digital delay. Analytical as well as simulation results are presented. Initial measurements from a 90 nm CMOS chip is provided for the transmitter and the full system, proving the feasibility of a digital future in radar.

Complementary Resistive Switches (CRS): High speed performance for the application in passive nanocrossbar arrays

2011 ◽  
Vol 1337 ◽  
Author(s):  
Roland Rosezin ◽  
Eike Linn ◽  
Lutz Nielen ◽  
Carsten Kügeler ◽  
Rainer Bruchhaus ◽  
...  
Keyword(s):  
High Speed ◽  
Simple Procedure ◽  
Electrical Characterization ◽  
Building Blocks ◽  
Next Generation ◽  
High Uniformity ◽  
Non Volatile Memory ◽  
Speed Performance ◽  
Resistive Switches

ABSTRACTIn this report, the fabrication and electrical characterization of fully vertically integrated complementary resistive switches (CRS), which consist of two anti-serially connected Cu-SiO2 memristive elements, is presented. The resulting CRS cells are initialized by a simple procedure and show high uniformity of resistance states afterwards. Furthermore, the CRS cells show high switching speeds below 50 ns, making them excellent building blocks for next generation non-volatile memory based on passive nanocrossbar arrays.

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