The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Alexander A. Balandin - One of the best experts on this subject based on the ideXlab platform.

  • low frequency Electronic Noise in superlattice and random packed thin films of colloidal quantum dots
    Nanoscale, 2019
    Co-Authors: Adane K Geremew, Caroline Qian, Alex Abelson, Sergey L Rumyantsev, Fariborz Kargar, Alexander A. Balandin
    Abstract:

    We report measurements of low-frequency Electronic Noise in ordered superlattice, weakly-ordered and random-packed thin films of 6.5 nm PbSe quantum dots prepared using several different ligand chemistries. For all samples, the normalized Noise spectral density of the dark current revealed a Lorentzian component, reminiscent of the generation–recombination Noise, superimposed on the 1/f background (f is the frequency). An activation energy of ∼0.3 eV was extracted from the temperature dependence of the Noise spectra in the ordered and random quantum dot films. The Noise level in the ordered films was lower than that in the weakly-ordered and random-packed films. A large variation in the magnitude of the Noise spectral density was also observed in samples with different ligand treatments. The obtained results are important for application of colloidal quantum dot films in photodetectors.

  • low frequency Electronic Noise in superlattice and random packed thin films of colloidal quantum dots
    arXiv: Mesoscale and Nanoscale Physics, 2019
    Co-Authors: Adane K Geremew, Caroline Qian, Alex Abelson, Sergey L Rumyantsev, Fariborz Kargar, Alexander A. Balandin
    Abstract:

    We report measurements of low-frequency Electronic Noise in ordered superlattice, weakly-ordered and random-packed thin films of 6.5 nm PbSe quantum dots prepared using several different ligand chemistries. For all samples, the normalized Noise spectral density of the dark current revealed a Lorentzian component, reminiscent of the generation-recombination Noise, superimposed on the 1/f background (f is the frequency). An activation energy of 0.3 eV was extracted from the temperature dependence of the Noise spectra. The Noise level in the ordered films was lower than that in the weakly-ordered and random-packed films. A large variation in the magnitude of the Noise spectral density was also observed in samples with different ligand treatments. The obtained results are important for application of colloidal quantum dot films in photodetectors.

  • low frequency Electronic Noise in quasi 1d tase3 van der waals nanowires
    Nano Letters, 2017
    Co-Authors: S L Rumyantsev, Matthew A Bloodgood, Tina T Salguero, M S Shur, Alexander A. Balandin
    Abstract:

    We report results of investigation of the low-frequency Electronic excess Noise in quasi-1D nanowires of TaSe3 capped with quasi-2D h-BN layers. Semimetallic TaSe3 is a quasi-1D van der Waals material with exceptionally high breakdown current density. It was found that TaSe3 nanowires have lower levels of the normalized Noise spectral density, SI/I2, compared to carbon nanotubes and graphene (I is the current). The temperature-dependent measurements revealed that the low-frequency Electronic 1/f Noise becomes the 1/f2 type as temperature increases to ∼400 K, suggesting the onset of electromigration (f is the frequency). Using the Dutta–Horn random fluctuation model of the Electronic Noise in metals, we determined that the Noise activation energy for quasi-1D TaSe3 nanowires is approximately EP ≈ 1.0 eV. In the framework of the empirical Noise model for metallic interconnects, the extracted activation energy, related to electromigration is EA = 0.88 eV, consistent with that for Cu and Al interconnects. Our...

  • graphene thickness graded transistors with reduced Electronic Noise
    Applied Physics Letters, 2012
    Co-Authors: S L Rumyantsev, M S Shur, Alexander A. Balandin
    Abstract:

    The authors demonstrate graphene thickness-graded transistors with high electron mobility and low 1/f Noise (f is a frequency). The device channel is implemented with few-layer graphene with the thickness varied from a single layer in the middle to few-layers at the source and drain contacts. It was found that such devices have electron mobility comparable to the reference single-layer graphene devices while producing lower Noise levels. The metal doping of graphene and difference in the electron density of states between the single-layer and few-layer graphene cause the observed Noise reduction. The results shed light on the Noise origin in graphene.

  • Low-Frequency Electronic Noise in the Back-Gated and Top-Gated Graphene Devices
    NATO Science for Peace and Security Series B: Physics and Biophysics, 2010
    Co-Authors: Qinghui Shao, Alexander A. Balandin, W. Stillman, Michal Shur, Sergey Rumyantsev
    Abstract:

    Graphene, which is a planar single sheet of sp2-bonded carbon atoms arranged in honeycomb lattice with superior electrical and heat conducting properties, has been proposed as material for future Electronic circuits, sensors and detectors. Practical applications of graphene devices require an acceptable level of the low-frequency 1/f γ Electronic Noise (f is frequency). We fabricated and investigated Electronic Noise characteristics in a set of back-gated and top-gated graphene field-effect transistors, which used single-layer and bi-layer graphene as the electrically conducting channel, and SiO2 and HfO2 as gate dielectrics. The Hooge parameter α H , which characterizes the Noise level, for the single and bi-layer graphene devices is on the order of α H ∼ 10−4–10−3, which is comparable to that in the state-of-the-art devices made of conventional semiconductors. The generation – recombination (G-R) – type bulges in the Noise spectra of some graphene devices suggest that the Noise is of the carrier-number fluctuation origin and is caused by the charge carrier trapping and de-trapping by defects in graphene and SiO2 layer. The obtained experimental results are important for Electronic and sensor applications of graphene.

Luca Varani - One of the best experts on this subject based on the ideXlab platform.

  • Terahertz-frequency Electronic Noise in In0.53Ga0.47As n+nn+ nanostructure
    Results in physics, 2020
    Co-Authors: Fatima Zohra Mahi, Luca Varani
    Abstract:

    Abstract In this article we present an analytical model for the calculation of high-frequency Electronic Noise in n+nn+ structure based on In0.53Ga0.47As material by using the analytical approach of Heterostructure Barrier Varactor (HBV) proposed in Ref. [1] . The model enables to interpret the different resonances appearing in the current and voltage spectral densities. In particular, we discuss the effect of geometrical parameters such as the total length of device and the free carriers concentration on the Noise resonance. The results can be useful in optimizing the device parameters for the generation of high frequency resonances Noise.

  • TeraHertz Electronic Noise in field-effect transistors
    Journal of Computational Electronics, 2014
    Co-Authors: Christophe Palermo, E. Starikov, Pavel Shiktorov, Viktoras Gružinskis, H. Marinchio, A. Mahi, Luca Varani
    Abstract:

    We present a theoretical investigation of high-frequency Electronic Noise in field-effect transistors used as detectors of TeraHertz radiation. Calculations are performed using the hydrodynamic-Langevin approach and specialized to the case of InGaAs high-electron mobility transistors. The main physical phenomena associated with the effect of branching of the total current between channel and gate and the appearance of two-dimensional plasma waves are discussed. We demonstrate that thermally excited standing plasma waves originate series of resonant peaks in the corresponding Noise spectral densities whose presence can be controlled by the embedding circuit. A significant damping of the high-frequency excess Noise is found when the transistor is submitted to a two-lasers optical photo-excitation presenting a beating frequency in the TeraHertz range. Finally, we discuss the dependence of the damping effect, as well as a shift of the resonance peaks from the presence of channel ungated regions.

  • Suppression of high-frequency Electronic Noise induced by 2D plasma waves in field-effect and high-electron-mobility transistors
    2011 21st International Conference on Noise and Fluctuations, 2011
    Co-Authors: H. Marinchio, E. Starikov, Luca Varani, Pavel Shiktorov, Christophe Palermo, Viktoras Gružinskis
    Abstract:

    A theoretical model based on simple hydrodynamic equations coupled with a pseudo-2D Poisson equation is used to calculate numerically and to analyze analitically Electronic Noise in FET/HEMT channels induced in the THz frequency range by the thermal excitation of 2D-plasma waves. The influence of ungated regions on high-frequency (HF) Noise is considered. An efficient suppression of HF Noise is found to take place in the case of additional ungated region placed between the gate and drain contacts.

  • Nonlocal effects and transfer fields for Electronic Noise in small devices
    Noise in Devices and Circuits II, 2004
    Co-Authors: Luca Varani, V. Gruzhinskis, Tomas Gonzalez, Daniel Pardo, Pavel Shiktorov, Jean Claude Vaissiere, Evjeni Starikov, Javier Mateos, L. Reggiani
    Abstract:

    This paper overviews and implements the transfer-field method applied to the calculation of Electronic Noise in small semiconductor structures. Two basic schemes are used and developed in detail. The former considers velocity fluctuations and the latter acceleration fluctuations as microcopic Noise sources. We show that the latter scheme has several advantages with respect to the former one. Indeed, starting from Markovian Noise sources, the latter scheme separates the time and spatial evolution of the local Noise sources. In this way, the dual representation of the Noise spectral density in terms of impedance and admittance fields is recovered. A remarkable achievement is that from the knowledge of the bulk Langevin sources at a hydrodynamic level it is possible to calculate the Noise spectra of non-homogeneous structures even for nanometric devices. The method is validated by comparing the results of the present scheme with those obtained from self-consistent Monte Carlo approaches for different structures of interest.

  • Monte Carlo Simulation of Electronic Noise under Large‐Signal Operation
    AIP Conference Proceedings, 2003
    Co-Authors: E. Starikov, Luca Reggiani, Luca Varani, Tomas Gonzalez, Pavel Shiktorov, Viktoras Gružinskis, Susana Perez, J. C. Vaissiere
    Abstract:

    We present Monte Carlo calculations of Electronic Noise in bulk materials and submicron semiconductor structures subject to periodic electric fields or voltage/current excitations of high frequency and large amplitude. The modifications of the Noise spectra with respect to the static case are analyzed. Under appropriate conditions the Noise spectra exhibit a resonant peak which is interpreted as upconversion of hot‐carrier intergroup Noise.

Mark C. Hersam - One of the best experts on this subject based on the ideXlab platform.

  • Low-frequency Electronic Noise in single-layer MoS2 transistors.
    Nano Letters, 2013
    Co-Authors: Vinod K. Sangwan, Heather N. Arnold, Deep Jariwala, Tobin J. Marks, Lincoln J. Lauhon, Mark C. Hersam
    Abstract:

    Ubiquitous low-frequency 1/f Noise can be a limiting factor in the performance and application of nanoscale devices. Here, we quantitatively investigate low-frequency Electronic Noise in single-layer transition metal dichalcogenide MoS2 field-effect transistors. The measured 1/f Noise can be explained by an empirical formulation of mobility fluctuations with the Hooge parameter ranging between 0.005 and 2.0 in vacuum (

  • low frequency Electronic Noise in single layer mos2 transistors
    Nano Letters, 2013
    Co-Authors: Vinod K. Sangwan, Heather N. Arnold, Deep Jariwala, Tobin J. Marks, Lincoln J. Lauhon, Mark C. Hersam
    Abstract:

    Ubiquitous low-frequency 1/f Noise can be a limiting factor in the performance and application of nanoscale devices. Here, we quantitatively investigate low-frequency Electronic Noise in single-layer transition metal dichalcogenide MoS2 field-effect transistors. The measured 1/f Noise can be explained by an empirical formulation of mobility fluctuations with the Hooge parameter ranging between 0.005 and 2.0 in vacuum (<10–5 Torr). The field-effect mobility decreased, and the Noise amplitude increased by an order of magnitude in ambient conditions, revealing the significant influence of atmospheric adsorbates on charge transport. In addition, single Lorentzian generation-recombination Noise was observed to increase by an order of magnitude as the devices were cooled from 300 to 6.5 K.

Ming Li - One of the best experts on this subject based on the ideXlab platform.

  • Monitoring the Shape of Satellite Wing Frame Using FBG Sensors in High Electronic Noise, Vacuum, and −196 °C Environment
    IEEE Transactions on Industrial Electronics, 2020
    Co-Authors: Ming Li
    Abstract:

    In a normal environment on Earth, there are several methods for obtaining the deflection curve of a satellite wing frame, such as the laser method and the Electronic resistance strain gauge method. However, none of them are suitable for the outer space environment. Therefore, developing a reliable sensing solution for a high Electronic Noise, vacuum, and extremely low-temperature environment may be a very challenging task. In this paper, a new fiber Bragg grating (FBG) sensors method is proposed to meet this harsh environment need. First, hundreds of FBG sensors are pasted onto the surface of a satellite wing frame to detect the strain data. Second, the cubic spline interpolation function, quadratic integral function, and quantic polynomial function are used for the data processing to obtain the shape of the satellite wing frame. Finally, a satellite wing frame is placed in a heat sink to conduct a shape monitoring experiment. Furthermore, a verification experiment in a normal environment shows the reliability of the FBG sensors method. Because the FBG sensors and the supporting equipment are available in the market, this method is a feasible solution for shape monitoring in outer space.

  • Monitoring the Shape of Satellite Wing Frame Using FBG Sensors in High Electronic Noise, Vacuum, and -196 °c Environment
    IEEE Transactions on Industrial Electronics, 2017
    Co-Authors: Peng Wei, Zejing Dai, Jie Liu, Ming Li
    Abstract:

    In a normal environment on Earth, there are several methods for obtaining the deflection curve of a satellite wing frame, such as the laser method and the Electronic resistance strain gauge method. However, none of them are suitable for the outer space environment. Therefore, developing a reliable sensing solution for a high Electronic Noise, vacuum, and extremely low-temperature environment may be a very challenging task. In this paper, a new fiber Bragg grating (FBG) sensors method is proposed to meet this harsh environment need. First, hundreds of FBG sensors are pasted onto the surface of a satellite wing frame to detect the strain data. Second, the cubic spline interpolation function, quadratic integral function, and quantic polynomial function are used for the data processing to obtain the shape of the satellite wing frame. Finally, a satellite wing frame is placed in a heat sink to conduct a shape monitoring experiment. Furthermore, a verification experiment in a normal environment shows the reliability of the FBG sensors method. Because the FBG sensors and the supporting equipment are available in the market, this method is a feasible solution for shape monitoring in outer space.

Vinod K. Sangwan - One of the best experts on this subject based on the ideXlab platform.

  • Low-frequency Electronic Noise in single-layer MoS2 transistors.
    Nano Letters, 2013
    Co-Authors: Vinod K. Sangwan, Heather N. Arnold, Deep Jariwala, Tobin J. Marks, Lincoln J. Lauhon, Mark C. Hersam
    Abstract:

    Ubiquitous low-frequency 1/f Noise can be a limiting factor in the performance and application of nanoscale devices. Here, we quantitatively investigate low-frequency Electronic Noise in single-layer transition metal dichalcogenide MoS2 field-effect transistors. The measured 1/f Noise can be explained by an empirical formulation of mobility fluctuations with the Hooge parameter ranging between 0.005 and 2.0 in vacuum (

  • low frequency Electronic Noise in single layer mos2 transistors
    Nano Letters, 2013
    Co-Authors: Vinod K. Sangwan, Heather N. Arnold, Deep Jariwala, Tobin J. Marks, Lincoln J. Lauhon, Mark C. Hersam
    Abstract:

    Ubiquitous low-frequency 1/f Noise can be a limiting factor in the performance and application of nanoscale devices. Here, we quantitatively investigate low-frequency Electronic Noise in single-layer transition metal dichalcogenide MoS2 field-effect transistors. The measured 1/f Noise can be explained by an empirical formulation of mobility fluctuations with the Hooge parameter ranging between 0.005 and 2.0 in vacuum (<10–5 Torr). The field-effect mobility decreased, and the Noise amplitude increased by an order of magnitude in ambient conditions, revealing the significant influence of atmospheric adsorbates on charge transport. In addition, single Lorentzian generation-recombination Noise was observed to increase by an order of magnitude as the devices were cooled from 300 to 6.5 K.