The aim of the work is to develop modeling equations which can be evolved into compact models generic to otfts rather than relying on the mosfetbased models for the modeling and simulation of. Comparison between classical and organic transistors in organic field effect transistor, the circulation of the current between the drain and the source is obtained by an applied gate voltage which actives the semiconductor. Abstract we improved the device performance of n,n ditridecyl3,4,9,10perylenetetracarboxylic diimide ptcdic ntype fieldeffect transistors, increasing electronmobility from 0. In this study, transparent gadoped zno gzo films grown by magnetron sputtering were used as the sourcedrain sd electrodes of bottomcontact organic. The transistor shows ambipolar transport characteristics with high electron and hole mobilities of 0. This research paper proposes analytical models for top and bottom contact organic field effect transistors by considering the overlapping of sourcedrain sd contacts on to the organic semiconductor layer and effective channel between the contacts. Organic transistor ot modeling, fabrication and applicability has undergone. Pdf modeling of top and bottom contact structure organic field. Schematic view of bottomgate bottom contacts thin film transistor. This study provides a simple approach to address the contact issue by incorporating an inducing layer prior to the organic semiconductor deposition. Pdf origin of characteristics differences between top and bottom.
Bottom contact ambipolar organic thin film transistor and. Shiyi liu et al 2018 nanotechnology 29 284001 view the article online for updates and enhancements. Related content performance improvement of a pentacene organic fieldeffect transistor through a dna interlayer wei shi, junsheng yu, wei huang et al. Displacement current in bottomcontact organic thinfilm transistor article in journal of physics d applied physics 41. Reducing contact resistance in bottom contact organic. We have succeeded in demonstrating an organic field effect transistor ofet. We investigated a bottomcontact transistor structure in which the source and drain contacts are deposited directly on the gate oxide followed by the deposition of the active organic layer.
Highperformance bottomcontact organic thinfilm transistors based on benzod,d. Our planar bottomcontact transistors show much higher mobility than conventional bottomcontact counterparts and. Pdf modeling of top and bottom contact structure organic. Comparison of top and bottomcontact organic thin film transistors. By adding a morphology modifying gold layer beneath the organic semiconductor. This work shows that placement of sourcedrain contacts on top of organic semiconductor film in topcontact organic thin film transistors otft can offer significant improvement in device speed as compared to bottomcontact devices.
Doped bottomcontact organic fieldeffect transistors iopscience. Improved ntype bottomcontact organic transistors by. Thickness dependence of mobility of pentacene planar. There are several types of ofet device structures with topcontact and bottomcontact systems. Displacement current in bottom contact organic thinfilm transistor to cite this article. Lots of efforts have been devoted to achieve comparable device performance with high charge carrier mobility and good air stability.
Organic thin film transistors otfts are being actively pursued. An organic thinfilm transistor otft having a lowdielectric polymer layer between gate insulator and sourcedrain electrodes is investigated. Charge transport characterized by phononassisted hoppingtunneling. Modeling of top and bottom contact structure organic field. Mobility overestimation due to gated contacts in organic. Engineers make worlds fastest organic transistor, heralding new generation of seethrough electronics teams from stanford and the university of nebraskalincoln collaborate to make thin, transparent semiconductors that could become the foundation for. The effect of surface treatment of bottom contact organic. Abstract one of the main challenges to achieve high. Bilayer processing for an enhanced organicelectrode.
Copper phthalocyanine cupc, a wellknown organic semiconductor, is used as an active layer to test performance of the device. An organic transistor has an organic semiconductor layer which includes at least one kind of compound represented by general formula 1. Enhanced performance of benzothieno3,2 b thiophene bttbased bottom contact thinfilm transistors. The highest mobility of the planar bottomcontact transistors is 0. The effect of surface treatment of bottom contact organic thin film transistor. Article critical evaluation of organic thinfilm transistor models markus krammer 1, james w. Meanwhile, the structure of the organic transistor may have a top gate or bottom gate structure depending on the position of a gate electrode, and the bottom gate structure may be divided into a top contact or bottom contact structure depending on whether the sourcedrain electrode is disposed on or below the semiconductor layer. This paper analyzes the behaviour of top contact tc and bottom contact bc otfts through charge drift model modifying in terms of device series resistance. The contact resistance in organic thinfilm transistors tfts is the limiting factor in the development of highfrequency organic tfts. Hsiuchieh chang youjhih liang chiehyuan feng chiaming yeh jiachong ho chengchung lee mingchou chen. Reducing contact resistance in bottom contact organic field effect.
Organic metal engineering for enhanced fieldeffect. Introduction to orgamoc electronics, fall 2005, dr. Bottom gate top contact bgtc and bottom gate bottom contact bgbc. Meanwhile, in order to reduce the fabrication costs, simple fabrication conditions such as the. The device includes a bottomcontact organic transistor, as described with respect to fig. For example, the organic photodetector may be fabricated on a region of substrate adjacent to the transistor, and the drain electrode 210 extended over this second.
Such a soft coplanar electrode provides a preferred configuration for bottomcontact organic fieldeffect transistors ofets, facilitating the studies on the fundamental properties of organic transistors, and showing strong potential for the development of largescale commercial organic transistor fabrication. An analytical approach for parameter extraction in linear. Doped bottomcontact organic fieldeffect transistors. Kummela integrated nanosensor lab, materials science and engineering program, department of physics. Chemically robust ambipolar organic transistor array. Photolithographycompatible conformal electrodes for high. Organic field effect transistors for large format electronics. Related content chevrontype short channel top contact otft minhoi kim, jinhyuk bae, wonho kim et al. Small contact resistance and highfrequency operation of flexible. Contact resistance in organic transistors that use source. The source contact of the mosfet is used as a reference throughout the following discussion.
Organic field effect transistor with a top contact transistor, b bottom contact transistor. Organic ambipolar transistor arrays for chemical sensors are prepared on a flexible plastic substrate with a bottom. Pdf modified transmission line model for bottom contact. Numerical simulations of organic fieldeffect transistors ofet of bottom and top contact boc, toc design with different sourcedrain contacts were carried out considering an exponential distribution of trap states in the gap of the active layer asi model.
The bottomcontact geometry simplifies the electric field distribution and the parasitic gate to sourcedrain overlap capacitance, and eliminates charge transport in the out. Moreover, this book discusses the impact of thickness variation of organic semiconductor and dielectric materials. Figure 4a demonstrates the typical transfer characteristics of bottom contact p. A ntype organic semiconductor, n,ndidodecyl3,4,9,10perylene tetracarboxylic diimide ptcdic 12 h 25, film crystallizes on various temperature substrates to act as active layer of organic thinfilm transistors otfts. Bilayer processing for an enhanced organic electrode contact in ultrathin bottom contact organic transistors jeongwon park, richard d. Organic tft thinfilm transistor tft structure and operation geometri and requirements. Hill department of physics, dalhousie university, halifax, nova scotia, canada. A 150 ppi organic thin film transistor otft array, which. Highresolution patterning technologies using inkjet. It is shown that the inclusion of a doped layer at the dielectric organic semiconductor layer leads to a signi. In organic electronics, most devices are currently fabricated using molecular or poly. Prospects and limitations of organic thin film transistors otfts. Enhanced performance of bottomcontact organic field. Bottomcontact organic thin film transistors with transparent ga.
Numerical simulations of contact resistance in organic thin. Electrolytic gated organic fieldeffect transistors for. Bottomcontact organic fieldeffect transistors having low. Pdf this research paper proposes analytical models for top and bottom contact organic field effect transistors by considering the overlapping of. In this paper, a complete analytical model of the conduction behavior of organic thinfilm transistors otfts within the framework of trap states has been presented. Bottom gate bottom contact top contact top gate g insulator s d semiconductor substrate g insulator s d. Numerical simulations of contact resistance in organic. Borchert 2, andreas petritz 3, esther karnerpetritz 3, gerburg schider 3, barbara stadlober 3, hagen klauk 2 and karin zojer 1 1 institute of solid state physics, nawi graz, graz university of technology, petersgasse 16, 8010 graz, austria. Since the bottomgate, bottomcontact dntt tfts show almost ideal transistor behavior with very small contact resistances, we have used them as a reference and analyzed them in detail. Subsequently, the drain and the gate voltages take into account the potential drop across the respective contacts. We have fabricated planar bottomcontact organic thinfilm transistors as a function of the thickness of the pentacene active layer. The larger channel width and long channel length of the substrates make them ideal for measuring poole.
Compared with bottomcontact devices, leakage current is reduced by roughly one. Critical evaluation of organic thinfilm transistor models. The gate electrode is immersed in the electrolyte and source and drain electrodes, isolated from the electrolyte, provide electrical contact to the channel figure1b. Displacement current in bottomcontact organic thinfilm. Furthermore, there is also a vertical transistor in which a carrier is movable vertically. Pss to gold sourcedrain sd electrodes, thereby reducing contact. Modified transmission line model for bottomcontact organic transistors article pdf available in ieee electron device letters 3410.
Pdf the differences in drain current and drain voltage idvd characteristics of top and bottom contact organic thin film transistors otfts are. Analysis of top and bottom contact organic transistor. The influence of doping on doped bottomgate bottomcontact organic fieldeffect transistors. Here, we present a simple approach to enhance the transmission and thus the current gain of a permeable base transistor. This research paper analyzes the performance of organic thin film transistor otft for two typical structures, viz. Flexible organic permeable base transistors are a promising transistor technology, enabling high transconductance without the need for costintensive structuring techniques. Organic fet with both n and ptype transport are called ambipolar.
Minimizing contact effects in organic semiconductorbased devices is a key step toward the development of a lowcost technology for nextgeneration electronics. The nuclear magnetic resonance 1d hydrogen spectroscopy 1hnmr was used to analyze molecular structure of the ptcdic 12 h 25. Doped bottomcontact organic fieldeffect transistors to cite this article. To provide an organic transistor having high mobility and a large current onoff ratio and exhibiting superior storage stability. Organic fieldeffect transistors have received much attention in the area of low cost, large area, flexible, and printable electronic devices. The gate electrodes of both two transistors were fabricated using ag nanoparticles ink by the surface energy controlled inkjet printing. For this study, we characterized the electrical properties of singlecrystal rubrene fieldeffect transistors fabricated in a bottom contact, bottom gate geometry fig. The performance of the resulting bottomcontact pentacene transistor is improved by two orders, and is comparable to the au topcontact devices. Study of ptcdic12h25based organic thin film transistors.
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