scholarly journals Nonlinearity Analysis of Quantum Capacitance and its Effect on Nano-Graphene Field Effect Transistor characteristics

2021 ◽  
Author(s):  
MUNINDRA MUNINDRA ◽  
DEVA NAND
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Drain Current ◽  
Charge Carrier Concentration ◽  
Single Layer Graphene ◽  
Quantum Capacitance ◽  
Large Area ◽  
Source Voltage ◽  
Current Calculation ◽  
The Impact

Abstract A simple, compact, and fundamental physics-based quasi-analytic model for Single layer graphene field effect transistors (GFETs) with large area graphene is presented in which the quantum mechanical density gradient method is utilised. The basic device physics of the two-dimensional (2D) graphene channel is studied analytically. This modeling leads to the precise drain current calculation of the GFETs. The drain current calculation for GFETs starts from charge carrier concentration, its density of states and quantum capacitance(QC). QC depends on the channel voltage as a function of gate to source voltage Vgs and drain to source voltage Vds primarily. The formulation of the drain current with velocity saturation has been done by the Monte Carlo simulation method. The performance of the analytical GFETs model is present the precise values of QC, its impact on drain current and transfer as well as output characteristics. The impact of QC at nanometer technology adds the nonlinearity to characteristics curves. The proposed method provides better results as compared with the previous analytical and simulated results.

Improving Stability of Pentacene Field-Effect Transistors with Post-Annealing

2007 ◽  
Vol 1029 ◽  
Author(s):  
Shun-Wei Liu ◽  
Jia-Cing Huang ◽  
Chih-Chien Lee ◽  
Chin-Ti Lee ◽  
Juen-Kai Wang
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Annealing Treatment ◽  
Drain Current ◽  
Semiconductor Layer ◽  
Post Annealing ◽  
Source Voltage ◽  
Effect Transistor ◽  
Improved Performance ◽  
Contact Field

AbstractIn this report, we demonstrate that the performance and stability of pentacene top-contact field-effect transistor can be greatly improved with post-annealing treatment. After post-annealing at 90°C for 12 hours in nitrogen environment, the hole field-effect mobility of 0.3 cm2/Vs and the on/off current ratio of 107 were achieved, demonstrating 100% improvement in performance after the post-annealing treatment. The decay rate of drain current at constant gate and drain-source voltage was found to be decreased by more than 40%. The improved performance is attributed to the elimination of trapped holes and lattice defects in the organic semiconductor layer due to the post-annealing process.

scholarly journals Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors

Biosensors ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Agnes Purwidyantri ◽  
Telma Domingues ◽  
Jérôme Borme ◽  
Joana Rafaela Guerreiro ◽  
Andrey Ipatov ◽  
...  
Keyword(s):  
Phosphate Buffer ◽  
Species Interactions ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Limit Of Detection ◽  
Debye Length ◽  
Intermolecular Forces ◽  
Single Layer Graphene ◽  
Dna Adsorption

Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity.

scholarly journals Experimental and molecular dynamics studies of an ultra-fast sequential hydrogen plasma process for fabricating phosphorene-based sensors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Rajabali ◽  
H. Asgharyan ◽  
V. Fadaei Naeini ◽  
A. Boudaghi ◽  
B. Zabihi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Dynamics ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Hydrogen Plasma ◽  
Device Fabrication ◽  
Dynamics Simulation ◽  
Red Phosphorus ◽  
Large Area ◽  
Low Concentration

AbstractLow concentration phosphorene-based sensors have been fabricated using a facile and ultra-fast process which is based on an exfoliation-free sequential hydrogen plasma treatment to convert the amorphous phosphorus thin film into mono- or few-layered phosphorene sheets. These sheets have been realized directly on silicon substrates followed by the fabrication of field-effect transistors showing the low leakage current and reasonable mobility for the nano-sensors. Being capable of covering the whole surface of the silicon substrate, red phosphorus (RP) coated substrate has been employed to achieve large area phosphorene sheets. Unlike the available techniques including mechanical exfoliation, there is no need for any exfoliation and/or transfer step which is significant progress in shortening the device fabrication procedure. These phosphorene sheets have been examined using transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Raman spectroscopy and atomic-force microscopy (AFM). Electrical output in different states of the crystallization as well as its correlation with the test parameters have been also extensively used to examine the evolution of the phosphorene sheets. By utilizing the fabricated devices, the sensitivity of the phosphorene based-field effect transistors to the soluble L-Cysteine in low concentrations has been studied by measuring the FET response to the different concentrations. At a gate voltage of − 2.5 V, the range of 0.07 to 0.60 mg/ml of the L-Cysteine has been distinguishably detected presenting a gate-controlled sensor for a low-concentration solution. A reactive molecular dynamics simulation has been also performed to track the details of this plasma-based crystallization. The obtained results showed that the imparted energy from hydrogen plasma resulted in a phase transition from a system containing red phosphorus atoms to the crystal one. Interestingly and according to the simulation results, there is a directional preference of crystal growth as the crystalline domains are being formed and RP atoms are more likely to re-locate in armchair than in zigzag direction.

scholarly journals Nanonet: Low-temperature-processed tellurium nanowire network for scalable p-type field-effect transistors and a highly sensitive phototransistor array

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Muhammad Naqi ◽  
Kyung Hwan Choi ◽  
Hocheon Yoo ◽  
Sudong Chae ◽  
Bum Jun Kim ◽  
...  
Keyword(s):  
Low Temperature ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistors ◽  
Optical Measurements ◽  
Electrical Performance ◽  
Large Area ◽  
Nanowire Network ◽  
P Type ◽  
Nanowire Networks

AbstractLow-temperature-processed semiconductors are an emerging need for next-generation scalable electronics, and these semiconductors need to feature large-area fabrication, solution processability, high electrical performance, and wide spectral optical absorption properties. Although various strategies of low-temperature-processed n-type semiconductors have been achieved, the development of high-performance p-type semiconductors at low temperature is still limited. Here, we report a unique low-temperature-processed method to synthesize tellurium nanowire networks (Te-nanonets) over a scalable area for the fabrication of high-performance large-area p-type field-effect transistors (FETs) with uniform and stable electrical and optical properties. Maximum mobility of 4.7 cm2/Vs, an on/off current ratio of 1 × 104, and a maximum transconductance of 2.18 µS are achieved. To further demonstrate the applicability of the proposed semiconductor, the electrical performance of a Te-nanonet-based transistor array of 42 devices is also measured, revealing stable and uniform results. Finally, to broaden the applicability of p-type Te-nanonet-based FETs, optical measurements are demonstrated over a wide spectral range, revealing an exceptionally uniform optical performance.

scholarly journals Large Area Emission in p-Type Polymer-Based Light-Emitting Field-Effect Transistors by Incorporating Charge Injection Interlayers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 901
Author(s):  
Gizem Acar ◽  
Muhammad Javaid Iqbal ◽  
Mujeeb Ullah Chaudhry
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Charge Injection ◽  
Limiting Factors ◽  
Hole Injection ◽  
Large Area ◽  
Device Structure ◽  
Light Emitting ◽  
Emission Area ◽  
P Type

Organic light-emitting field-effect transistors (LEFETs) provide the possibility of simplifying the display pixilation design as they integrate the drive-transistor and the light emission in a single architecture. However, in p-type LEFETs, simultaneously achieving higher external quantum efficiency (EQE) at higher brightness, larger and stable emission area, and high switching speed are the limiting factors for to realise their applications. Herein, we present a p-type polymer heterostructure-based LEFET architecture with electron and hole injection interlayers to improve the charge injection into the light-emitting layer, which leads to better recombination. This device structure provides access to hole mobility of ~2.1 cm2 V−1 s−1 and EQE of 1.6% at a luminance of 2600 cd m−2. Most importantly, we observed a large area emission under the entire drain electrode, which was spatially stable (emission area is not dependent on the gate voltage and current density). These results show an important advancement in polymer-based LEFET technology toward realizing new digital display applications.

scholarly journals All-Organic, Low Voltage, Transparent and Compliant Organic Field-Effect Transistor Fabricated by Means of Large-Area, Cost-Effective Techniques

2020 ◽  
Vol 10 (19) ◽  
pp. 6656
Author(s):  
Stefano Lai ◽  
Giulia Casula ◽  
Pier Carlo Ricci ◽  
Piero Cosseddu ◽  
Annalisa Bonfiglio
Keyword(s):  
Field Effect ◽  
Low Voltage ◽  
Field Effect Transistors ◽  
High Mobility ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Large Area ◽  
Parylene C ◽  
Biomedical Sensing ◽  
Novel Applications

The development of electronic devices with enhanced properties of transparency and conformability is of high interest for the development of novel applications in the field of bioelectronics and biomedical sensing. Here, a fabrication process for all organic Organic Field-Effect Transistors (OFETs) by means of large-area, cost-effective techniques such as inkjet printing and chemical vapor deposition is reported. The fabricated device can operate at low voltages (as high as 4 V) with ideal electronic characteristics, including low threshold voltage, relatively high mobility and low subthreshold voltages. The employment of organic materials such as Parylene C, PEDOT:PSS and 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS pentacene) helps to obtain highly transparent transistors, with a relative transmittance exceeding 80%. Interestingly enough, the proposed process can be reliably employed for OFET fabrication over different kind of substrates, ranging from transparent, flexible but relatively thick polyethylene terephthalate (PET) substrates to transparent, 700-nm-thick, compliant Parylene C films. OFETs fabricated on such sub-micrometrical substrates maintain their functionality after being transferred onto complex surfaces, such as human skin and wearable items. To this aim, the electrical and electromechanical stability of proposed devices will be discussed.

Preparation of integrated chemical sensors using commercial VLSI technology

1987 ◽  
Vol 65 (5) ◽  
pp. 1072-1078 ◽  
Author(s):  
Paul G. Glavina ◽  
D. Jed Harrison
Keyword(s):  
Chemical Sensors ◽  
Linear Response ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Microelectrode Arrays ◽  
Drain Current ◽  
Cyclic Voltammetric ◽  
Design Rules ◽  
Vlsi Technology ◽  
Commercial Technology

The fabrication of ion sensitive field effect transistors (ISFET) and microelectrode arrays for use as chemical sensors using a commercial CMOS fabrication process is described. The commercial technology is readily available through the Canadian Microelectronics Corporation; however, several of the recommended design rules must be ignored in preparing chemical sensors using this process. The ISFET devices show near theoretical response to K+ in aqueous solution (55 mV slope) when coated with a K+ sensitive membrane. An extended gate ion sensitive device is presented which offers advantages in encapsulation of ISFET sensors. The source-drain current of both devices show a linear response to log [Formula: see text] in contrast to ISFETs previously reported that have high internal lead resistances. Al and poly-Si microelectrode arrays are fabricated commercially and then Pt is electrodeposited on the microelectrodes. The resulting arrays show good cyclic voltammetric response to Fe(CN)64− and Ru(NH3)63+ and are relatively durable.

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