scholarly journals Parallel Potentiometric and Capacitive Response in a Water-Gate Thin Film Transistor Biosensor at High Ionic Strength

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5618
Author(s):  
Hadi AlQahtani ◽  
Abdullah Alswieleh ◽  
Ibrahim Al-Khurayyif ◽  
Saad AlGarni ◽  
Martin Grell
Keyword(s):  
Thin Film ◽  
Ionic Strength ◽  
Thin Film Transistor ◽  
High Ionic Strength ◽  
Spike Protein ◽  
Model Parameters ◽  
Response Characteristics ◽  
Potentiometric Response ◽  
Water Gate ◽  
Output Characteristics

We show that an SnO2-based water-gate thin film transistor (WGTFT) biosensor responds to a waterborne analyte, the spike protein of the SARS-CoV-2 virus, by a parallel potentiometric and capacitive mechanism. We draw our conclusion from an analysis of transistor output characteristics, which avoids the known ambiguities of the common analysis based on transfer characteristics. Our findings contrast with reports on organic WGTFT biosensors claiming a purely capacitive response due to screening effects in high ionic strength electrolytes, but are consistent with prior work that clearly shows a potentiometric response even in strong electrolytes. We provide a detailed critique of prior WGTFT analysis and screening reasoning. Empirically, both potentiometric and capacitive responses can be modelled quantitatively by a Langmuir‒Freundlich (LF) law, which is mathematically equivalent to the Hill equation that is frequently used for biosensor response characteristics. However, potentiometric and capacitive model parameters disagree. Instead, the potentiometric response follows the Nikolsky-Eisenman law, treating the analyte ‘RBD spike protein’ as an ion carrying two elementary charges. These insights are uniquely possible thanks to the parallel presence of two response mechanisms, as well as their reliable delineation, as presented here.

Indium–gallium–zinc–oxide thin-film transistor with a planar split dual-gate structure

2017 ◽  
Vol 31 (35) ◽  
pp. 1750332
Author(s):  
Yu-Rong Liu ◽  
Jie Liu ◽  
Jia-Qi Song ◽  
Pui-To Lai ◽  
Ruo-He Yao
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistor ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Practical Applications ◽  
Gate Structure ◽  
Dual Gate ◽  
Indium Gallium ◽  
Output Characteristics

An amorphous indium–gallium–zinc–oxide (a-IGZO) thin-film transistor (TFT) with a planar split dual gate (PSDG) structure has been proposed, fabricated and characterized. Experimental results indicate that the two independent gates can provide dynamical control of device characteristics such as threshold voltage, sub-threshold swing, off-state current and saturation current. The transconductance extracted from the output characteristics of the device increases from [Formula: see text] to [Formula: see text] for a change of control gate voltage from −2 V to 2 V, and thus the device could be used in a variable-gain amplifier. A significant advantage of the PSDG structure is its flexibility in controlling the device performance according to the need of practical applications.

scholarly journals Experiments and Thermodynamic Modeling of Chukanovite (Fe2(OH)2CO3) to High Ionic Strengths

MRS Advances ◽  
2017 ◽  
Vol 2 (13) ◽  
pp. 747-752 ◽  
Author(s):  
Sungtae Kim ◽  
Justin Dean ◽  
Jandi Knox ◽  
Leslie Kirkes ◽  
Je-Hun Jang
Keyword(s):  
Free Energy ◽  
Ionic Strength ◽  
Room Temperature ◽  
Xrd Analysis ◽  
High Ionic Strength ◽  
Model Parameters ◽  
Second Phase ◽  
Experimental Conditions ◽  
Ph Values ◽  
Decreasing Ph

ABSTRACTWhile conducting siderite (FeCO3) solubility experiments in NaCl-Na2CO3 brines, evidence for a second phase was detected. Experiments, in which synthesized siderite was reacted with high ionic strength (0.18 – 7.5 m) solutions at room temperature and high pH (>10), were conducted in a glovebox. As the aging time of siderite-bearing experiments increased, the pH of the solution decreased, signaling formation of a hydroxyl-bearing phase. Decreasing pH values are interpreted to indicate that a hydroxyl-bearing phase, such as chukanovite, is the reaction controlling solid in the solid assemblage. Chukanovite was tentatively identified by XRD analysis. We set out, therefore, to determine the thermodynamic stability of chukanovite under the experimental conditions. Aqueous thermodynamic model parameters were determined with experimentally analyzed Fe(II) solubility data, and subsequently yielded a proposed formation free energy of chukanovite (-1149.8 kJ/mol).

scholarly journals The Investigation of Indium-Free Amorphous Zn-Al-Sn-O Thin Film Transistor Prepared by Magnetron Sputtering

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 585
Author(s):  
Mingyu Zhang ◽  
Kuankuan Lu ◽  
Zhuohui Xu ◽  
Honglong Ning ◽  
Xiaochen Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistor ◽  
Localized States ◽  
Oxide Semiconductor ◽  
High Definition ◽  
Force Microscopy ◽  
Amorphous Oxide Semiconductor ◽  
Photoconductivity Decay ◽  
Output Characteristics ◽  
New Generation

The indium-free amorphous oxide semiconductor thin film transistor (AOS-TFT) with aluminum (Al) electrodes shows broad application prospects in new-generation display technologies, such as ultra-high definition large-screen display, OLED display and 3D display. In this work, the thin film transistor (TFT) with a zinc-aluminum-tin-oxide (ZATO) semiconductor as the active layer and an Al electrodes as the source and drain (S/D) was investigated. The optical, electrical and semiconductive properties of the ZATO films were evaluated by atomic force microscopy (AFM), ultraviolet–visible spectrophotometry and microwave photoconductivity decay (μ-PCD), respectively. The result shows that the film is smooth and transparent and has low localized states and defects at a moderate oxygen concentration (~5%) and a low sputtering gas pressure (~3 mTorr). After the analysis of the transfer and output characteristics, it can be concluded that the device exhibits an optimal performance at the 623 K annealing temperature with an Ion/Ioff ratio of 5.5 × 107, an SS value of 0.15 V/decade and a saturation mobility (μsat) of 3.73 cm2·V−1·s−1. The ZATO TFT at the 623 K annealing has a −8.01 V negative shift under the −20 V NBS and a 2.66 V positive shift under the 20 V PBS.

scholarly journals Feasibility of a silicon thin film transistor-based aptamer sensor for COVID-19 detection

2020 ◽  
Author(s):  
Thomas Farrow ◽  
Siriny Laumier ◽  
Steve Hall ◽  
Ian Sandall ◽  
Harm van Zalinge
Keyword(s):  
Thin Film ◽  
Early Diagnosis ◽  
Linear Response ◽  
Thin Film Transistor ◽  
Spike Protein ◽  
Silicon Thin Film ◽  
Current Testing ◽  
Diagnosis And Management ◽  
Aptamer Sensor

Abstract Since the beginning of the coronavirus disease 2019 (COVID-19) in December 2019 and the current lack to date of specific drugs or vaccinations to cope with the disease, it has become apparent that the surest way of dealing with this is through early diagnosis and management. Current testing has shown to be unable to rapidly and accurately provide the results required to restrict the spread. Here we report feasibility for the use of an intrinsic silicon thin film transistor functionalised with aptamers designed to attach to the spike protein of COVID-19. It is shown that a linear response can be obtained in a concentration range of 1 pM to 1 nM.

Light/electric modulated approach for logic functions and artificial synapse behaviors by flexible IGZO TFTs with low power consumption

2021 ◽  
Author(s):  
Liqiang Guo ◽  
Guifa Zhang ◽  
Hui Han ◽  
Yongbin Hu ◽  
Guanggui Cheng
Keyword(s):  
Thin Film ◽  
Low Power ◽  
Visible Light ◽  
Electron Mobility ◽  
Thin Film Transistor ◽  
Operating Voltage ◽  
High Electron ◽  
Response Characteristics ◽  
Logic Operations ◽  
Logic Functions

Abstract In recent years, low power electronic devices have attracted more and more interests. Here, flexible thin-film transistors(TFTs) with In-Ga-Zn-O (IGZO) as semiconductor channel material were fabricated on polyethylene terephthalate (PET) substrates. The device exhibits good electrical properties at low operating voltage, including high on/off ratio of ~ 7.8 × 106 and high electron mobility of ~ 23.1 cm2V-1s-1. The device also has excellent response characteristics to visible light. With the increase of visible light intensity, the threshold voltage of IGZO TFTs decreases continuously, but the electron mobility increases gradually. Based on the unique response ability of the device to light, we proposed and demonstrated that a single thin-film transistor can realize different logic operations under the light/electricity mixed modulation, including “AND” and “OR”. In addition, we also simulated some basic artificial synaptic behaviors, including excitatory postsynaptic current and paired-pulse facilitation. Thus, IGZO TFTs operating at low voltages not only have the potential to construct multifunctional optoelectronic devices, but also provide a new idea for simplifying the design of programmable logic circuits.

The response characteristics of odor sensor based on organic thin-film transistor for environment malodor measurements

2011 ◽  
Vol 11 (4) ◽  
pp. S163-S166
Author(s):  
Jin Wook Jeong ◽  
Young Wook Park ◽  
Tae Hyun Park ◽  
Jin Hwan Choi ◽  
Hyun Ju Choi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistor ◽  
Organic Thin Film ◽  
Organic Thin Film Transistor ◽  
Response Characteristics

scholarly journals Raised Source/Drain (RSD) and Vertical Lightly Doped Drain (LDD) Poly-Si Thin-Film Transistor

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 103
Author(s):  
Feng-Tso Chien ◽  
Jing Ye ◽  
Wei-Cheng Yen ◽  
Chii-Wen Chen ◽  
Cheng-Li Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Electric Field ◽  
Electric Fields ◽  
Systems Engineering ◽  
Impact Ionization ◽  
Thin Film Transistor ◽  
Ionization Rate ◽  
Drain Side ◽  
Output Characteristics ◽  
Lightly Doped Drain

The raised source/drain (RSD) structure is one of thin film transistor designs that is often used to improve device characteristics. Many studies have mentioned that the high impact ionization rate occurring at a drain side can be reduced, owing to a raised source/drain area that can disperse the drain electric field. In this study, we will discuss how the electric field at the drain side of an RSD device is reduced by a vertical lightly doped drain (LDD) scheme rather than a RSD structure. We used different raised source/drain forms to simulate the drain side electric field for each device, as well as their output characteristics, using Integrated Systems Engineering (ISE-TCAD) simulators. Different source and drain thicknesses and doping profiles were applied to verify the RSD mechanism. We found that the electric fields of a traditional device and uniform doping RSD structures are almost the same (~2.9 × 105 V/cm). The maximum drain electric field could be reduced to ~2 × 105 V/cm if a vertical lightly doped drain RSD scheme was adopted. A pure raised source/drain structure did not benefit the device characteristics if a vertical lightly doped drain design was not included in the raised source/drain areas.

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