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Biasing

About: Biasing is a research topic. Over the lifetime, 29422 publications have been published within this topic receiving 301035 citations.


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Journal ArticleDOI
TL;DR: This work reports an ultra-broadband bolometric photodetector based on a suspended CNT film that demonstrates a high performance with an ultraviolet responsivity of up to 0.58 A/W with a bias voltage of 0.2 V and a short response time of ∼150 μs in vacuum, which is better than that of many otherPhotodetectors based on CNTs.
Abstract: Ultra-broad spectral detection is critical for several technological applications in imaging, sensing, spectroscopy, and communication. Carbon nanotube (CNT) films are a promising material for ultra-broadband photodetectors because their absorption spectra cover the entire ultraviolet to the terahertz range. However, because of the high binding energy of excitons, photodetectors based on CNT films always require a strong electric field, asymmetric electrical contacts, or hybrid structures with other materials. Here, we report an ultra-broadband bolometric photodetector based on a suspended CNT film. With an abundant distribution of tube diameters and an appropriate morphology (spider web-like), the CNT films display a strong absorption spectrum from the ultraviolet up to the terahertz region. Under illumination, heat generated from the electron-photon interaction dominates the photoresponse of our devices. For small changes in temperature, the photocurrent shows a convincing linear dependence with the absorbed light's power across 3 orders of magnitude. When the channel length is reduced to 100 μm, the device demonstrates a high performance with an ultraviolet responsivity of up to 0.58 A/W with a bias voltage of 0.2 V and a short response time of ∼150 μs in vacuum, which is better than that of many other photodetectors based on CNTs. Moreover, this performance could be further enhanced by optimization.

56 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of bias voltage on structural, mechanical and tribological properties of the diamond-like carbon (DLC) films was investigated, and the correlation between the structure, mechanical properties and wear resistance of the DLC films was presented.

56 citations

Journal ArticleDOI
TL;DR: In this paper, a low-noise wideband read-out electronics for dc superconducting quantum interference devices (SQUIDs) is presented, which can be operated with both dc bias and ac bias of up to 250 kHz.
Abstract: A low-noise wideband read-out electronics for dc superconducting quantum interference devices (SQUIDs) is presented. The preamplifier which is directly connected to the SQUID has white voltage and current noise levels of 0.4 nV//spl radic/Hz and 6.2 pA//spl radic/Hz with 1/f corners at 0.2 Hz and 13 Hz, respectively. The SQUID can be operated with both dc bias and ac bias of up to 250 kHz. In the latter case, a special circuit synchronously detects the ac bias component at the preamplifier output and automatically removes it by tuning the bias voltage. An in-system programmable microcontroller is used to control all functions of the SQUID system via a serial RS-485 interface. It also generates the ac bias clock and sets the SQUID working point via low-noise D/A converters. The read-out electronics has been used to operate low-noise SQUID magnetometers. Noise levels down to 35 fT//spl radic/Hz and 0.9 fT//spl radic/Hz with 1/f corners at about 2 Hz have been achieved with thin-film SQUID magnetometers operated at 77 K and 4.2 K, respectively. With static bias a high bandwidth of up to 6 MHz was achieved without affecting the noise level. With 100 kHz bias reversal the rms noise increased by about 3% when increasing the system bandwidth from 100 kHz to 1.4 MHz. The system slew rate was 0.4 /spl Phi//sub 0///spl mu/s to 2.3 /spl Phi//sub 0///spl mu/s. A short integrator reset time of <1 /spl mu/s allows one to increase the dynamic range utilizing the periodicity of the SQUID voltage vs. flux characteristic.

56 citations

Journal ArticleDOI
TL;DR: In this article, an electrically tunable reflectarray metasurface for two dimensional (2D) beam steering is designed by integration of a thin layer of indium tin oxide (ITO) material into a metal-insulator-metal (MIM) plasmonic unitcell.
Abstract: In this paper, an electrically tunable reflectarray metasurface for two dimensional (2D) beam steering is designed by integration of a thin layer of indium tin oxide (ITO) material into a metal-insulator-metal (MIM) plasmonic unit-cell. The reflectarray is composed of square-shaped patch nanoantennas placed on a stack of insulator-ITO-metallic ground plane. The resonant characteristic of unit-cell and the accumulation of carrier density at the interface of ITO-insulator play key roles in obtaining over 250° of phase agility at around 218 terahertz (THz), by electrically varying the bias voltage. An array of unit-cells with integrated ITO and 2D voltage biasing distribution (from the side) offer the possibility of designing a reconfigurable antenna in which the main beam can be steered to relatively large angles in both θ- and - planes at carefully selected operating frequency. The significant advantage of this design is the dynamically adjustable radiation pattern in both azimuth and elevation planes even after fabrication.

56 citations

Journal ArticleDOI
TL;DR: In this paper, a porous silicon (PS) optical cavity is demonstrated for the electroluminescence (EL) PS diode configuration, which is composed of a thin Au film, a light-emitting PS layer, a multilayered PS mirror, a p-type Si substrate, and an ohmic contact.
Abstract: It is demonstrated that a porous silicon (PS) optical cavity is available for the electroluminescence (EL) PS diode configuration. The PS diode is composed of a thin Au film, a light‐emitting PS layer, a multilayered PS mirror, a p‐type Si substrate, and an ohmic contact. When a sufficient bias voltage is applied to the diode, a uniform visible light emission is observed through the top contact. The EL intensity is fairly proportional to the driving current over a wide range of operation. The bandwidth of the EL spectrum is significantly reduced in comparison to that of the conventional PS diodes, owing to a resonance effect induced between the Au film and the multilayered PS mirror. These results suggest that the PS technology is a promising process for applications in monolithic integrated optoelectronics.

56 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023256
2022488
2021480
2020923
2019946
2018977