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Journal ArticleDOI

Photo-Response of Low Voltage Flexible TIPS-Pentacene Organic Field-Effect Transistors

15 Jun 2017-IEEE Sensors Journal (IEEE)-Vol. 17, Iss: 12, pp 3689-3697
TL;DR: In this paper, photo-response of solution processed flexible TIPS-pentacene organic field effect transistors is evaluated under illumination with visible light of red, green, and blue colors having minimum wavelengths of 620, 520, and 460 nm.
Abstract: Photo-response of solution processed flexible TIPS-pentacene organic field-effect transistors is evaluated under illumination with visible light of red, green, and blue colors having minimum wavelengths of 620, 520, and 460 nm. For −10 V operation, pristine photo-OFETs exhibited average field-effect mobility of 0.11 cm $^{2}\text{V}^{-1}\text{s}^{-1}$ , near zero threshold voltage, and current ON–OFF ratio of ~105. These photo-OFETs exhibited prevalent photovoltaic characteristics with shift in the threshold voltage upon illumination, which was found to increase with rising intensity, illumination time, and gate bias during illumination. For low-voltage operation at −5 V, maximum current modulation of $4\times 10^{4}$ and 102, and photo-responsivity of 17 mA/W and 35 mA/W, respectively, were achieved for blue (intensity of 1.7 mW/cm2) and green (intensity of 0.4 mW/cm2) light illuminations. However, these photo-OFETs did not show significant response to red light. A fast dynamic response to periodic pulses of illumination was also observed. For a gate bias of +10 V and illumination time of 500 s, maximum current modulation of 105 was achieved for blue light illumination.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the optical non-volatile memory characteristics using CuPc OFET were comprehensively demonstrated with different programming conditions, and it was found that the programming of the OFET with an electric pulse at the gate terminal under UV-light photo-illumination compared to other programming conditions could substantially increase the memory window due to massive charge trapping in the polymer electret layer.

3 citations

Journal ArticleDOI
TL;DR: A simple vertical organic field-effect transistor (VOFET) structure has been fabricated using ambipolar 6, 13-bis (triisopropylsilyl ethynyl) pentacene (TIPSP) with a channel length of 90 nm, for the first time the authors are using transistor efficiency to extract VOFET's parameters.
Abstract: A simple vertical organic field-effect transistor (VOFET) structure has been fabricated using ambipolar 6, 13-bis (triisopropylsilyl ethynyl) pentacene (TIPSP) with a channel length (L) of 90 nm. This device can operate at –2 V which is much lower than the voltage, reported so far for the organic devices based on TIPSP. The first time, the authors are using transistor efficiency to extract VOFET's parameters. The threshold voltage (V th) of the device has been found to vary between 0.18 and 0.38 V with the current on/off ratio (I on /I off) of 104. The mobility (µ) of the device has been calculated as 0.62 cm2/Vs. The sub-threshold slope, transconductance (gm ), output conductance (g d), and early voltage (V E) have been found to be 140 ± 30 mV/decade, 2 µS, 10−6 S, and 1.3 ± 2 V, respectively.

2 citations

Journal ArticleDOI
21 Feb 2023-Sensors
TL;DR: In this article , the most relevant FoM of a DNTT-based organic phototransistor as a function of the timing parameters of light pulses, to assess the device suitability for real-time applications, was derived.
Abstract: The photosensitivity, responsivity, and signal-to-noise ratio of organic phototransistors depend on the timing characteristics of light pulses. However, in the literature, such figures of merit (FoM) are typically extracted in stationary conditions, very often from IV curves taken under constant light exposure. In this work, we studied the most relevant FoM of a DNTT-based organic phototransistor as a function of the timing parameters of light pulses, to assess the device suitability for real-time applications. The dynamic response to light pulse bursts at ~470 nm (close to the DNTT absorption peak) was characterized at different irradiances under various working conditions, such as pulse width and duty cycle. Several bias voltages were explored to allow for a trade-off to be made between operating points. Amplitude distortion in response to light pulse bursts was also addressed.

1 citations

Proceedings ArticleDOI
01 Mar 2019
TL;DR: In this paper, the effect of UV irradiation on the electrical performance of OFETs with CuPc as active layer is demonstrated, and the devices have shown stable electrical performance under dark with avg. and max. field effect mobility of $( 1.0 \pm 0.3 ) \times 10 ^{-2}$ and $1.4 \times 6.5 cm $ 2
Abstract: Effect of UV irradiation $( \lambda _{Peak} \quad =365$ nm) on the electrical performance of the OFETs with CuPc as active layer is demonstrated. The devices have shown stable electrical performance under dark with avg. and max. field effect mobility of $( 1.0 \pm 0.3 ) \times 10 ^{-2}$ and $1.4 \times 10 ^{-2}$ cm $^{2}\, \mathrm {V}^{-1}\, \mathrm {s}^{-1}$ respectively. Under UV illumination there found a shift in threshold voltage and change in ON current along with fast response and recovery time of 0.4 s and 2 s respectively with periodic UV ON-OFF pulses.

1 citations

Proceedings ArticleDOI
01 Oct 2017
TL;DR: In this paper, the effect of thermal annealing on the performance of flexible OFETs was investigated and it was found that an annealed device exhibited a larger decay in drain current than a pristine device under constant bias stress.
Abstract: Effect of thermal annealing on the performance of flexible OFETs was investigated. Annealing at low temperatures up to 50 °C enhanced the molecular ordering and granular arrangement leading to improved device performance, however, a permanent degradation was induced at high temperature annealing due to loss in crystallinity and crack generation. An annealed device exhibited a larger decay in drain current than a pristine device under constant bias stress. Under combined effects of mechanical and thermal stress, effect of thermal stress was found to be dominant at higher annealing temperatures, resulting in monotonic performance degradation.
References
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Journal ArticleDOI
21 Jul 2011-Nature
TL;DR: It is shown that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid–air interfaces.
Abstract: Printing electronic devices using semiconducting 'ink' is seen as a promising route to cheap, large-area and flexible electronics, but the performance of such devices suffers from the relatively poor crystallinity of the printed material. Hiromi Minemawari and colleagues have developed an inkjet-based printing technique involving controlled mixing on a surface of two solutions — the semiconductor (C8-BTBT) in its solvent and a liquid in which the semiconductor is insoluble. The products of this antisolvent crystallization technique are thin semiconductor films with exceptionally high and uniform crystallinity. The use of single crystals has been fundamental to the development of semiconductor microelectronics and solid-state science1. Whether based on inorganic2,3,4,5 or organic6,7,8 materials, the devices that show the highest performance rely on single-crystal interfaces, with their nearly perfect translational symmetry and exceptionally high chemical purity. Attention has recently been focused on developing simple ways of producing electronic devices by means of printing technologies. ‘Printed electronics’ is being explored for the manufacture of large-area and flexible electronic devices by the patterned application of functional inks containing soluble or dispersed semiconducting materials9,10,11. However, because of the strong self-organizing tendency of the deposited materials12,13, the production of semiconducting thin films of high crystallinity (indispensable for realizing high carrier mobility) may be incompatible with conventional printing processes. Here we develop a method that combines the technique of antisolvent crystallization14 with inkjet printing to produce organic semiconducting thin films of high crystallinity. Specifically, we show that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid–air interfaces. Using this approach, we have printed single crystals of the organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) (ref. 15), yielding thin-film transistors with average carrier mobilities as high as 16.4 cm2 V−1 s−1. This printing technique constitutes a major step towards the use of high-performance single-crystal semiconductor devices for large-area and flexible electronics applications.

1,505 citations


"Photo-Response of Low Voltage Flexi..." refers background in this paper

  • ...SOLUTION processed organic field effect transistors (OFETs) are receiving global attention as alternatives to their inorganic counterparts because of various advantages, low cost and simplicity being prime among many [1]–[5]....

    [...]

Journal ArticleDOI
TL;DR: In this review, recent developments in the area of high-electron-mobility diimides based on rylenes and related aromatic cores, particularly perylene- and naphthalene-diimide-based small molecules and polymers, for application in high-performance organic field-effect transistors and photovoltaic cells are summarized and analyzed.
Abstract: Organic electron-transporting materials are essential for the fabrication of organic p-n junctions, photovoltaic cells, n-channel field-effect transistors, and complementary logic circuits. Rylene diimides are a robust, versatile class of polycyclic aromatic electron-transport materials with excellent thermal and oxidative stability, high electron affinities, and, in many cases, high electron mobilities; they are, therefore, promising candidates for a variety of organic electronics applications. In this review, recent developments in the area of high-electron-mobility diimides based on rylenes and related aromatic cores, particularly perylene- and naphthalene-diimide-based small molecules and polymers, for application in high-performance organic field-effect transistors and photovoltaic cells are summarized and analyzed.

1,494 citations

Journal ArticleDOI
TL;DR: An approach--termed fluid-enhanced crystal engineering (FLUENCE)--that allows for a high degree of morphological control of solution-printed thin films and may find use in the fabrication of high-performance, large-area printed electronics.
Abstract: Solution coating of organic semiconductors offers great potential for achieving low-cost manufacturing of large-area and flexible electronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of thin-film morphology. Here, we report an approach—termed fluid-enhanced crystal engineering (FLUENCE)—that allows for a high degree of morphological control of solution-printed thin films. We designed a micropillar-patterned printing blade to induce recirculation in the ink for enhancing crystal growth, and engineered the curvature of the ink meniscus to control crystal nucleation. Using FLUENCE, we demonstrate the fast coating and patterning of millimetre-wide, centimetre-long, highly aligned single-crystalline organic semiconductor thin films. In particular, we fabricated thin films of 6,13-bis(triisopropylsilylethynyl) pentacene having non-equilibrium single-crystalline domains and an unprecedented average and maximum mobilities of 8.1±1.2 cm2 V−1 s−1 and 11 cm2 V−1 s−1. FLUENCE of organic semiconductors with non-equilibrium single-crystalline domains may find use in the fabrication of high-performance, large-area printed electronics. Solution printing of organic semiconductors could in principle be scaled to industrial needs, yet attaining aligned single-crystals directly with this method has been challenging. By using a micropillar-patterned printing blade designed to enhance the control of crystal nucleation and growth, thin films of macroscopic, highly aligned single crystals of organic semiconductors can now be fabricated.

876 citations


"Photo-Response of Low Voltage Flexi..." refers background in this paper

  • ...TIPS-pentacene crystals were found to exhibit their general terracing morphology [39], [40]....

    [...]

Journal ArticleDOI
TL;DR: This optimised polymer semiconductor represents a significant progress in semiconductor development, dispelling prevalent skepticism surrounding practical usability of organic semiconductors for high-performance microelectronic devices, opening up application opportunities hitherto functionally or economically inaccessible with silicon technologies, and providing an excellent structural framework for fundamental studies of charge transport in organic systems.
Abstract: Microelectronic circuits/arrays produced via high-speed printing instead of traditional photolithographic processes offer an appealing approach to creating the long-sought after, low-cost, large-area flexible electronics. Foremost among critical enablers to propel this paradigm shift in manufacturing is a stable, solution-processable, high-performance semiconductor for printing functionally capable thin-film transistors — fundamental building blocks of microelectronics. We report herein the processing and optimisation of solution-processable polymer semiconductors for thin-film transistors, demonstrating very high field-effect mobility, high on/off ratio, and excellent shelf-life and operating stabilities under ambient conditions. Exceptionally high-gain inverters and functional ring oscillator devices on flexible substrates have been demonstrated. This optimised polymer semiconductor represents a significant progress in semiconductor development, dispelling prevalent skepticism surrounding practical usability of organic semiconductors for high-performance microelectronic devices, opening up application opportunities hitherto functionally or economically inaccessible with silicon technologies, and providing an excellent structural framework for fundamental studies of charge transport in organic systems.

825 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide a basic physical description of the exciton diffusion in organic semiconductors and present experimental methods that are used to measure the key parameters of this process.
Abstract: The purpose of this review is to provide a basic physical description of the exciton diffusion in organic semiconductors. Furthermore, experimental methods that are used to measure the key parameters of this process as well as strategies to manipulate the exciton diffusion length are summarized. Special attention is devoted to the temperature dependence of exciton diffusion and its relationship to Forster energy transfer rates. An extensive table of more than a hundred measurements of the exciton diffusion length in various organic semiconductors is presented. Finally, an outlook of remaining challenges for future research is provided.

659 citations


"Photo-Response of Low Voltage Flexi..." refers background in this paper

  • ...Excitons which are generated in the vicinity of interface (distance shorter than diffusion length), can reach to interface, and contribute towards photo-induced effects [49]–[51]....

    [...]