Analysis of Drain Currents During Switching off a-Si:H Based Thin Film Transistors

1998 ◽  
Vol 507 ◽  
Author(s):  
F. Lemmi ◽  
R. A. Street
Keyword(s):  
Thin Film ◽  
Fermi Level ◽  
Defect Density ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Depletion Region ◽  
Time Range ◽  
Defect States ◽  
Current Decay ◽  
Decay Times

ABSTRACTWe present measurements and analysis of a-Si:H thin film transistor (TFT) transients when the gate voltage switches the device from a conducting to a non-conducting state. The drain current transient has been monitored in the medium-long (Ims-100s) time range and exhibits a power law decay extending to at least 10 seconds. The decay has been studied over a range of drain voltages and gate off-state voltages. Measured data show that the gate off-state can help to obtain a low drain leakage current at long times when high drain voltages are being used.However, the decay at low drain voltages shows little sensitivity to different gate off-state voltages. An analytical model is developed, based on the relaxation of the Fermi level toward mid-gap in a spatially uniform TFT channel. The model shows how deep defects are responsible for the current decay slope at long times, while shallower states determine the slope in the short time range. An energy-independent defect density would produce a 1/t slope for the current decay. Shallow states and deep states affect in opposite ways the slope since their density is energydependent in opposite ways as Fermi level moves deeper into the band-gap. Furthermore, long decay times are associated with a wider depletion region in the channel and increase the total number of defect states involved. A steeper decay than 1/t is expected and observed for shorttime ranges, while a more gradual (about 1/t1/2) one corresponds to long time measurements. The implications of the transient decay for the performance of active matrix arrays will be discussed.

Lanthanum Doping Enabling High Drain Current Modulation in a p-Type Tin Monoxide Thin-Film Transistor

2019 ◽  
Vol 11 (50) ◽  
pp. 47025-47036 ◽  
Author(s):  
Sungyeon Yim ◽  
Taikyu Kim ◽  
Baekeun Yoo ◽  
Hongwei Xu ◽  
Yong Youn ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Lanthanum Doping ◽  
Current Modulation ◽  
P Type ◽  
Tin Monoxide

scholarly journals Double-gate thin film transistor with suspended-gate applicable to tactile force sensor

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
An Hoang-Thuy Nguyen ◽  
Manh-Cuong Nguyen ◽  
Seongyong Cho ◽  
Anh-Duy Nguyen ◽  
Hyewon Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Force Sensor ◽  
Air Gap ◽  
Insulator Layer ◽  
Highly Sensitive ◽  
Highly Sensitive Sensors ◽  
Effective Integration

Abstract This paper presents a straightforward, low-cost, and effective integration process for the fabrication of membrane gate thin film transistors (TFTs) with an air gap. The membrane gate TFT with an air gap can be used as the highly sensitive tactile force sensor. The suspended membrane gate with an air gap as the insulator layer is formed by multiple photolithography steps and photoresist sacrificial layers. The viscosity of the photoresist and the spin speed was used to modify the thickness of the air gap during the coating process. The tactile force was measured by monitoring the drain current of the TFT as the force changed the thickness of the air gap. The sensitivity of the devices was enhanced by an optimal gate size and low Young’s modulus of the gate material. This simple process has the potential for the production of small, versatile, and highly sensitive sensors.

Modelling and Simulation Approach for Organic Thin-Film Transistors Using MATLAB Simulation

2015 ◽  
Vol 1107 ◽  
pp. 514-519
Author(s):  
Umar Faruk Shuib ◽  
Khairul Anuar Mohamad ◽  
Afishah Alias ◽  
Tamer A. Tabet ◽  
Bablu K. Gosh ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Mobility Model ◽  
Channel Length ◽  
Analytical Models ◽  
Organic Thin Film ◽  
Organic Thin Film Transistor ◽  
Organic Transistor

As organic transistors are preparing to make improvements towards flexible and low cost electronics applications, the analytical models and simulation methods were demanded to predict the optimized performance and circuit design. In this paper, we investigated the analytical model of an organic transistor device and simulate the output and transfer characteristics of the device using MATLAB tools for different channel length (L) of the organic transistor. In the simulation, the Pool-Frenkel mobility model was used to represent the conductive channel of organic transistor. The different channel length has been simulated with the value of 50 μm, 10 μm and 5 μm. This research paper analyses the performance of organic thin film transistor (TFT) for top contact bottom gate device. From the simulation, drain current of organic transistor was increased as the channel length decreased. Other extraction value such sub-threshold and current on/off ratio is 0.41 V and 21.1 respectively. Thus, the simulation provides significant extraction of information about the behaviour of the organic thin film transistor.

Analysis of Carrier Transport Mechanism for p-Type SnO Thin-Film Transistor

2017 ◽  
Vol 748 ◽  
pp. 122-126
Author(s):  
Jian Qin ◽  
Lei Qiang
Keyword(s):  
Thin Film ◽  
Carrier Transport ◽  
Conduction Mechanism ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Thermally Activated ◽  
Multiple Trapping ◽  
P Type ◽  
Tin Monoxide ◽  
Thermally Activated Process

Temperature effect on the I-V characteristics of tin monoxide thin film transistors (SnO TFTs) has been analyzed. The result shows that the drain current of the SnO TFT obeys the Meyer-Neldel rule under low temperature, where current conduction is a thermally activated process. The carrier transport would be dominated by multiple trapping conduction, while, percolation conduction mechanism holds as the temperature increase.

Modeling of depletion width variation over time in thin film photovoltaics

2016 ◽  
Vol 30 (05) ◽  
pp. 1650044 ◽  
Author(s):  
Marouf Aldosari ◽  
Liliana Grigoriu ◽  
Hamed Sohrabpoor ◽  
Nima E. Gorji
Keyword(s):  
Thin Film ◽  
Carrier Transport ◽  
Defect Density ◽  
Depletion Region ◽  
Time Dependent ◽  
Perovskite Layer ◽  
Tunneling Mechanism ◽  
Depletion Width ◽  
Thin Film Photovoltaics ◽  
Over Time

The performance degradation of a hybrid solar cell is modelled considering the variation of depletion width over time. The p-i-n structure of a TiO2/perovskite/HTL photovoltaic is investigated. Several different time-dependent approaches are compared and a new model is introduced based on the variation of defect density over time in depletion region. This phenomenon consequently manifests itself in the device degradation. Our approach leads to rather complicated time-dependent equation for the defect density which takes into account also the non-uniformity of electric field in the depletion region. The thickness of TiO2 nano layer is taken 50 nm and perovskite layer is 330 nm. The nanoscale thickness of TiO2 layer warrants the carrier transport through tunneling mechanism.

scholarly journals Performance Enhancement of Pentacene-Based Organic Thin-Film Transistors Using a High-K PVA/Low-K PVP Bilayer as the Gate Insulator

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3941
Author(s):  
Ching-Lin Fan ◽  
Hou-Yen Tsao ◽  
Yu-Shien Shiah ◽  
Che-Wei Yao ◽  
Po-Wei Cheng
Keyword(s):  
Thin Film ◽  
Performance Enhancement ◽  
Gate Dielectric ◽  
Thin Film Transistor ◽  
Control Sample ◽  
Drain Current ◽  
Gate Insulator ◽  
Organic Thin Film ◽  
High K ◽  
Low K

In this study, we proposed using the high-K polyvinyl alcohol (PVA)/low-K poly-4-vinylphenol (PVP) bilayer structure as the gate insulator to improve the performance of a pentacene-based organic thin-film transistor. The dielectric constant of the optimal high-K PVA/low-K PVP bilayer was 5.6, which was higher than that of the single PVP layer. It resulted in an increase in the gate capacitance and an increased drain current. The surface morphology of the bilayer gate dielectric could be suitable for pentacene grain growth because the PVP layer was deposited above the organic PVA surface, thereby replacing the inorganic surface of the ITO gate electrode. The device performances were significantly improved by using the bilayer gate dielectric based upon the high-K characteristics of the PVA layer and the enlargement of the pentacene grain. Notably, the field-effect mobility was increased from 0.16 to 1.12 cm2/(Vs), 7 times higher than that of the control sample.

Effects of Device Architecture on the Performance of Organic Thin Film Transistors

2008 ◽  
Vol 1138 ◽  
Author(s):  
Xiaojing Zhou ◽  
Karyn E. Mutkins ◽  
Daniel Elkington ◽  
Kathleen Sirois ◽  
Warwick Belcher ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Channel Length ◽  
Device Performance ◽  
Organic Thin Film ◽  
Organic Thin Film Transistor ◽  
Device Architecture ◽  
Electrochemical Transistor ◽  
The Impact

AbstractThe impact of device dimension and architecture on the device performance of an all–solution fabrication organic thin film transistor (OTFT) has been investigated. The saturation drain current is inversely proportional to the channel length, indicating that a characteristic of field–effect like transistor has been obtained. In contrast, the drain current is independent of the thickness of polyvinylphenol (PVP) dielectric layer and a large leakage current is observed at the gate electrode indicating that the device also shows electrochemical transistor characteristics. Although separate conductance measurements of a single poly(3–hexylthiophene) (P3HT) layer and a P3HT/PVP layer reveal that the conductance is proportional to the thickness of the layer, the maximum achieved drain current in the fabricated OTFT is inversely proportional to the P3HT thickness. Using this data, an interface of P3HT/PVP or a maximum P3HT thickness for a working transistor of approximately 160 ± 16 nm can be extracted. The mechanism of operation of these devices is discussed.

Photoresponses of Zinc Tin Oxide Thin-Film Transistor

2020 ◽  
Vol 20 (3) ◽  
pp. 1704-1708
Author(s):  
Wei Lun Huang ◽  
Chen-Chuan Yang ◽  
Sheng-Po Chang ◽  
Shoou-Jinn Chang
Keyword(s):  
Thin Film ◽  
Tin Oxide ◽  
Thin Film Transistor ◽  
Drain Current ◽  
Oxide Thin Film ◽  
Current Ratio ◽  
Uv Photodetector ◽  
Saturation Region ◽  
Zinc Tin Oxide ◽  
Sputtering System

In this study, the optical and electrical properties of a zinc tin oxide (ZTO) thin-film transistor (TFT) were investigated. The TFT was fabricated using ZTO as the active layer, which was deposited by a radio frequency magnetron sputtering system, to form an ultraviolet (UV) photodetector. The device has a threshold voltage of 0.48 V, field-effect mobility of 1.47 cm2/Vs in the saturation region, on/off drain current ratio of 2×106, and subthreshold swing of 0.45 V/decade in a dark environment. Moreover, as a UV photodetector, the device has a long photoresponse time, responsivity of 0.329 A/W, and rejection ratio of 3.19×104 at a gate voltage of -15 V under illumination of wavelength 300 nm.

Electrically active organic and polymeric materials for thin-film-transistor technologies

1996 ◽  
Vol 11 (6) ◽  
pp. 1581-1592 ◽  
Author(s):  
Andrew J. Lovinger ◽  
Lewis J. Rothberg
Keyword(s):  
Thin Film ◽  
Thin Film Transistor ◽  
Polymeric Materials ◽  
Drain Current ◽  
Current Status ◽  
Flat Panel Display ◽  
Semiconducting Materials ◽  
Flat Panel ◽  
Technological Potential ◽  
Potential Alternative

Organic and polymeric materzials have seen a tremendous growth in research in the last five years as potential electroactive elements in thin-film-transistor (TFT) applications. These are driven by the increasing interest in flat-panel-display applications, for which organic and polymeric materials offer strong promise in terms of properties, processability, cost, and compatibility with eventual lightweight, flexible plastic displays. In this review we summarize the current status of our knowledge on the science of these organic and polymeric semiconducting materials. Most of these are based on linear thiophenes, especially a-hexathienyl, which has elicited by far the most attention. Mobility values in the 10−2–10−1 cm2/Vs and especially source-drain current on/off ratios of up to 106 make this a highly promising potential alternative to amorphous silicon. Other thienyl compounds are also discussed, as are polymeric analogues. A brief discussion of technological potential, limitations, and problems that need to be overcome is given at the end.

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