Large-area low-noise flexible organic photodiodes for detecting faint visible light

Science ◽  
2020 ◽  
Vol 370 (6517) ◽  
pp. 698-701
Author(s):  
Canek Fuentes-Hernandez ◽  
Wen-Fang Chou ◽  
Talha M. Khan ◽  
Larissa Diniz ◽  
Julia Lukens ◽  
...  
Keyword(s):  
Low Cost ◽  
Low Frequency ◽  
Low Noise ◽  
Visible Spectral Range ◽  
Limited Area ◽  
Bulk Heterojunctions ◽  
Large Area ◽  
Detection Technology ◽  
Level Performance

Silicon photodiodes are the foundation of light-detection technology; yet their rigid structure and limited area scaling at low cost hamper their use in several emerging applications. A detailed methodology for the characterization of organic photodiodes based on polymeric bulk heterojunctions reveals the influence that charge-collecting electrodes have on the electronic noise at low frequency. The performance of optimized organic photodiodes is found to rival that of low-noise silicon photodiodes in all metrics within the visible spectral range, except response time, which is still video-rate compatible. Solution-processed organic photodiodes offer several design opportunities exemplified in a biometric monitoring application that uses ring-shaped, large-area, flexible, organic photodiodes with silicon-level performance.

A new fabrication technique for directly coupled transmural cardiac electrodes

1988 ◽  
Vol 254 (4) ◽  
pp. H804-H810 ◽  
Author(s):  
F. X. Witkowski ◽  
P. A. Penkoske
Keyword(s):  
Three Dimensional ◽  
Low Frequency ◽  
Low Noise ◽  
Base Line ◽  
Stainless Steel Needle ◽  
Arrhythmia Mechanisms ◽  
Electrophysiological Characterization ◽  
Sintered Ag

Many current attempts at electrophysiological elucidation of cardiac arrhythmia mechanisms have centered around activation sequence mapping. This is most commonly performed with polarized unipolar or bipolar metal electrodes, which, because of unstable direct current (DC) base-line potentials, necessitate alternating current (AC)-coupled amplification. An ideal nonpolarizable unipolar electrode offers unhindered exchange of charge allowing for stable DC recordings of biological electrical activity. In addition to activation information, DC unipolar recordings enable quantitation of systolic and diastolic potentials, other low-frequency phenomena of interest such as repolarization, as well as rapid recovery from such rapid extreme potential shifts such as defibrillation. Previous attempts to apply nonpolarizable electrodes to transmural cardiac investigations required complex wick electrode techniques to prevent mechanical movement of the fluid-metal interface when chlorided silver wire was used. We have developed a technique to fabricate miniature sintered Ag-AgCl electrodes that are mounted at various locations on a 20-gauge stainless steel needle permitting stable transmural DC unipolar electrogram recordings in vivo. The electrodes are low noise, rugged, sterilizable, and reusable and should prove useful in three-dimensional electrophysiological characterization of the heart.

Design of ECG Signal Acquisition and Processing Circult

2012 ◽  
Vol 236-237 ◽  
pp. 856-861 ◽  
Author(s):  
Jing Ma ◽  
Jun Xu ◽  
Hai Bo Xu ◽  
Yu Wang ◽  
Sheng Xu Yin
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Low Frequency ◽  
Low Noise ◽  
Cardiac Conduction ◽  
Signal Acquisition ◽  
Ecg Signal ◽  
Physiological Signal ◽  
Heart Study ◽  
Low Pass

ECG signal is, as a vital method performed on the heart study and clinical diagnosis of cardiovascular diseases, an important human physiological signal, containing the human cardiac conduction system of physiological and pathological information. Aiming at the weak low frequency characteristic of ECG signals, the core circuit based on the AD620 and LM324 amplifier is given. After analyzing the major components of the ECG signal and the frequency range of interference, weak ECG signal collected by the electrodes is amplified by the preamplifier circuit, and the interference then is wiped out by using a low-pass filer, a high-pass filer, 50Hz notch filer and back amplifier circuit, finally a right wave of ECG is received. The characteristics of the system features the merits of high input impedance, high CMRR, low noise, less excursion and high SNR(signal to noise ratio), low cost and so on.

Research on Magnetoelectric Seismometer's Low Frequency Extension Technology

2014 ◽  
Vol 664 ◽  
pp. 268-273
Author(s):  
Yun Tian Teng ◽  
Xing Xing Hu ◽  
Hong Ya Lu
Keyword(s):  
Frequency Response ◽  
Low Cost ◽  
Low Frequency ◽  
High Sensitivity ◽  
Inertial Mass ◽  
Negative Resistance ◽  
Low Noise ◽  
Corner Frequency ◽  
Filter Method ◽  
High Frequency Response

Magnetoelectric seismometer has many outstanding features, such as low cost, small size, light weight, high sensitivity, low noise, good high frequency response, and reliable operation, simple set up, so these type of seismometer is widely used in several areas. However, because the structure of magnetoelectric seismometer (inertial mass and elastic support module), there has the material and mechanical structure limitation, so the inherent frequency is around between 5 to 30Hz, hard to be lower, hence, the low frequency characteristic is poor. To extend the seismometer's range of application, post compensation is needed. The researchers from both home and aboard proposed many different method to deal with the low frequency response of this seismometer, such as “inverse filter” method, “Lippmann” method, which uses negative resistance and feedback coil. These methods have got some results separately. In this paper, we will propose a low frequency integral method to extend the seismometer's frequency response. It is accomplished through balanced integration and high precision chips to suppress the circuit drifting and noise interference. The results from vibration table shows, after integration, the seismometer's low frequency corner frequency is extended from 2 Hz to under 0.1 Hz, the sensitivity is enhanced from 200V/m·s-1 to 400V/m·s-1.

scholarly journals A Compact Size Wideband RF-VGA Based on Second Generation Controlled Current Conveyors

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1600
Author(s):  
J. del Pino ◽  
Sunil L. Khemchandani ◽  
D. Galante-Sempere ◽  
C. Luján-Martínez
Keyword(s):  
Power Consumption ◽  
Second Generation ◽  
Low Cost ◽  
Low Frequency ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Current Conveyors ◽  
Compact Size ◽  
Sige Bicmos ◽  
Controlled Current Conveyors

This paper presents a methodology to design a wideband radio frequency variable gain amplifier (RF-VGA) in a low-cost SiGe BiCMOS 0.35 μm process. The circuit uses two Class A amplifiers based on second-generation controlled current conveyors (CCCII). The main feature of this circuit is the wideband input match along with a reduced NF (5.5–9.6 dB) and, to the authors’ knowledge, the lowest die footprint reported (62 × 44 μm2 area). The implementation of the RF-VGA based on CCCII allows a wideband input match without the need of passive elements. Due to the nature of the circuit, when the gain is increased, the power consumption is reduced. The architecture is suitable for designing wideband, low-power, and low-noise amplifiers. The proposed design achieves a tunable gain of 6.7–18 dB and a power consumption of 1.7 mA with a ±1.5 V DC supply. At maximum gain, the proposed RF-VGA covers from DC up to 1 GHz and can find application in software design radios (SDRs), the low frequency medical implant communication system (MICS) or industrial, scientific, and medical (ISM) bands.

scholarly journals White Noise Characterization of N-MOSFETs for Physics-Based Cryogenic Device Modeling

2021 ◽  
Author(s):  
Kenji Ohmori ◽  
Shuhei Amakawa
Keyword(s):  
White Noise ◽  
Variable Temperature ◽  
Low Frequency ◽  
Low Noise ◽  
Broadband Noise ◽  
Noise Amplifier ◽  
Cryogenic Chamber ◽  
Noise Characterization ◽  
First Time

<p>We propose a methodology of variable-temperature broadband noise characterization for cryogenic MOSFETs. A DUT is mounted on a reusable PCB <i>vehicle</i> with a built-in low-noise amplifier, and loaded into a cryogenic chamber. Using the vehicle, we measured flicker (low frequency) and white noise, and have successfully revealed dominance of shot noise in the temperature range from 300 to 120 K for the first time.</p>

Mechanical and Material Characterization of Bilayer Microcantilever-based IR detectors

2011 ◽  
Vol 1299 ◽  
Author(s):  
I-Kuan Lin ◽  
Ping Du ◽  
Yanhang Zhang ◽  
Xin Zhang
Keyword(s):  
Material Characterization ◽  
Low Cost ◽  
Isothermal Holding ◽  
Low Noise ◽  
Device Performance ◽  
Ir Detectors ◽  
Element Analysis ◽  
Noise Equivalent Temperature Difference ◽  
Ir Detection

ABSTRACTInfrared radiation (IR) detection and imaging are of great importance to a variety of military and civilian applications. Microcantilever-based IR detectors have recently gained a lot of interest because of their potential to achieve extremely low noise equivalent temperature difference (NETD) while maintaining low cost to make them affordable to more applications. However, the curvature induced by residual strain mismatch within the microcantilever severely decreases the device performance. To meet performance and reliability requirement, it is important to fully understand the deformation of IR detectors. Therefore, the purpose of this study is threefold: (1) to develop an engineering approach to flatten IR detectors, (2) to model and predict the elastic deformation of IR detectors using finite element analysis (FEA), and (3) to study the inelastic deformation during isothermal holding.

scholarly journals White Noise Characterization of N-MOSFETs for Physics-Based Cryogenic Device Modeling

2021 ◽  
Author(s):  
Kenji Ohmori ◽  
Shuhei Amakawa
Keyword(s):  
White Noise ◽  
Variable Temperature ◽  
Low Frequency ◽  
Low Noise ◽  
Broadband Noise ◽  
Noise Amplifier ◽  
Cryogenic Chamber ◽  
Noise Characterization ◽  
First Time

<p>We propose a methodology of variable-temperature broadband noise characterization for cryogenic MOSFETs. A DUT is mounted on a reusable PCB <i>vehicle</i> with a built-in low-noise amplifier, and loaded into a cryogenic chamber. Using the vehicle, we measured flicker (low frequency) and white noise, and have successfully revealed dominance of shot noise in the temperature range from 300 to 120 K for the first time.</p>

scholarly journals Fabrication and Characterization of a Marine Wet Solar Cell with Titanium Dioxide and Copper Oxides Electrodes

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Htoo Nay Wunn ◽  
Shinichi Motoda ◽  
Motoaki Morita
Keyword(s):  
Titanium Dioxide ◽  
Solar Cell ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Cell Voltage ◽  
Copper Oxides ◽  
Marine Environments ◽  
Large Area ◽  
Photocatalytic Effect

One of the effective ways of utilizing marine environments is to generate energy, power, and hydrogen via the effect of photocatalysts in the seawater. Since the ocean is vast, we are able to use its large area, but the power generation system must be of low cost and have high durability against both force and corrosion. In order to meet those requirements, this study focuses on the fabrication of a novel marine wet solar cell composed of a titanium dioxide photoanode and a copper oxide photocathode. These electrodes were deposited on type 329J4L stainless steel, which possesses relative durability in marine environments. This study focuses on the characterization of the photocatalytic properties of electrodes in seawater. Low-cost manufacturing processes of screen-printing and vacuum vapor deposition were applied to produce the titanium dioxide and copper oxides electrodes, respectively. We investigated the photopotential of the electrodes, along with the electrochemical properties and cell voltage properties of the cell. X-ray diffraction spectroscopy (XRD) of the copper oxides electrode was analyzed in association with the loss of photocatalytic effect in the copper oxides electrode. Although the conversion efficiency of the wet cell was less than 1%, it showed promising potential for use in marine environments with low-cost production. Electrochemical impedance spectroscopy (EIS) of the cell was also conducted, from which impedance values regarding the electrical properties of electrodes and their interfaces of charge-transfer processes were obtained. This study focuses on the early phase of the marine wet solar cell, which should be further studied for long-term stability and in actual marine environmental applications.

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