Related content chevrontype short channel top contact otft minhoi kim, jinhyuk bae, wonho kim et al. Organic field effect transistors for large format electronics. 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. Copper phthalocyanine cupc, a wellknown organic semiconductor, is used as an active layer to test performance of the device. Analysis of top and bottom contact organic transistor. Improved ntype bottomcontact organic transistors by. Mobility overestimation due to gated contacts in organic. Furthermore, there is also a vertical transistor in which a carrier is movable vertically. Abstract one of the main challenges to achieve high.
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. Organic transistor ot modeling, fabrication and applicability has undergone. Compared with bottomcontact devices, leakage current is reduced by roughly one. Related content performance improvement of a pentacene organic fieldeffect transistor through a dna interlayer wei shi, junsheng yu, wei huang et al. Critical evaluation of organic thinfilm transistor models. Our planar bottomcontact transistors show much higher mobility than conventional bottomcontact counterparts and.
A 150 ppi organic thin film transistor otft array, which. 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 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. Abstract we improved the device performance of n,n ditridecyl3,4,9,10perylenetetracarboxylic diimide ptcdic ntype fieldeffect transistors, increasing electronmobility from 0. Actually, an egofet looks like an oect organic electrochemical transistor. An organic thinfilm transistor otft having a lowdielectric polymer layer between gate insulator and sourcedrain electrodes is investigated. The transistor shows ambipolar transport characteristics with high electron and hole mobilities of 0. Reducing contact resistance in bottom contact organic field effect. Pdf modeling of top and bottom contact structure organic field. Chemically robust ambipolar organic transistor array. To provide an organic transistor having high mobility and a large current onoff ratio and exhibiting superior storage stability.
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. 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. Lots of efforts have been devoted to achieve comparable device performance with high charge carrier mobility and good air stability. Pdf modeling of top and bottom contact structure organic. Subsequently, the drain and the gate voltages take into account the potential drop across the respective contacts. Shiyi liu et al 2018 nanotechnology 29 284001 view the article online for updates and enhancements. Reducing contact resistance in bottom contact organic. The source contact of the mosfet is used as a reference throughout the following discussion. Prospects and limitations of organic thin film transistors otfts. Bilayer processing for an enhanced organic electrode contact in ultrathin bottom contact organic transistors jeongwon park, richard d. We report on the fabrication and characterization of the bottom contact organic thin film transistor and inverter based on a heterostructure of c 60 on pentacene. The contact effect is investigated in the proposed models and further verified through twodimensional 2d. Kummela integrated nanosensor lab, materials science and engineering program, department of physics. Modified transmission line model for bottomcontact organic transistors article pdf available in ieee electron device letters 3410.
Bottomcontact organic thin film transistors with transparent ga. The effect of surface treatment of bottom contact organic. Numerical simulations of contact resistance in organic thin. Organic metal engineering for enhanced fieldeffect. Electrolytic gated organic fieldeffect transistors for. Bilayer processing for an enhanced organicelectrode. By adding a morphology modifying gold layer beneath the organic semiconductor. We have fabricated planar bottomcontact organic thinfilm transistors as a function of the thickness of the pentacene active layer. The nuclear magnetic resonance 1d hydrogen spectroscopy 1hnmr was used to analyze molecular structure of the ptcdic 12 h 25. Pdf origin of characteristics differences between top and bottom. The performance of the resulting bottomcontact pentacene transistor is improved by two orders, and is comparable to the au topcontact devices. Minimizing contact effects in organic semiconductorbased devices is a key step toward the development of a lowcost technology for nextgeneration electronics. The highest mobility of the planar bottomcontact transistors is 0. Displacement current in bottomcontact organic thinfilm.
Source and drain electrodes made of cu or ag in organic fieldeffect transistors are treated with an organic acceptor, dimethyldicyanoquinonediimine dmdcnqi. Organic fet with both n and ptype transport are called ambipolar. We have succeeded in demonstrating an organic field effect transistor ofet. Organic thin film transistors otfts are being actively pursued. Highresolution patterning technologies using inkjet. Schematic view of bottomgate bottom contacts thin film transistor. Displacement current in bottom contact organic thinfilm transistor to cite this article. Study of ptcdic12h25based organic thin film 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. Bottomcontact organic fieldeffect transistors having low. The influence of doping on doped bottomgate bottomcontact organic fieldeffect transistors. Modeling of top and bottom contact structure organic field.
For this study, we characterized the electrical properties of singlecrystal rubrene fieldeffect transistors fabricated in a bottom contact, bottom gate geometry fig. 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. 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. Moreover, this book discusses the impact of thickness variation of organic semiconductor and dielectric materials. This study provides a simple approach to address the contact issue by incorporating an inducing layer prior to the organic semiconductor deposition. The effect of surface treatment of bottom contact organic thin film transistor. Organic fieldeffect transistors have received much attention in the area of low cost, large area, flexible, and printable electronic devices. There are ptype organic semiconductors with hole carriers, ntype organic semiconductors with electron carriers and ambipolar organic semiconductors with both.
The larger channel width and long channel length of the substrates make them ideal for measuring poole. Enhanced performance of bottomcontact organic field. 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. Thickness dependence of mobility of pentacene planar. Organic ambipolar transistor arrays for chemical sensors are prepared on a flexible plastic substrate with a bottom. An organic transistor has an organic semiconductor layer which includes at least one kind of compound represented by general formula 1. The device includes a bottomcontact organic transistor, as described with respect to fig. Flexible organic permeable base transistors are a promising transistor technology, enabling high transconductance without the need for costintensive structuring techniques. 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. The gate electrodes of both two transistors were fabricated using ag nanoparticles ink by the surface energy controlled inkjet printing. Figure 4a demonstrates the typical transfer characteristics of bottom contact p.
Doped bottomcontact organic fieldeffect transistors to cite this article. Hill department of physics, dalhousie university, halifax, nova scotia, canada. Bottom contact ambipolar organic thin film transistor and. Organic field effect transistor with a top contact transistor, b bottom contact transistor. Small contact resistance and highfrequency operation of flexible. 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. 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.
There are several types of ofet device structures with topcontact and bottomcontact systems. Numerical simulations of contact resistance in organic. 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. Charge transport characterized by phononassisted hoppingtunneling. It is shown that the inclusion of a doped layer at the dielectric organic semiconductor layer leads to a signi. The contact resistance in organic thinfilm transistors tfts is the limiting factor in the development of highfrequency organic tfts. In organic electronics, most devices are currently fabricated using molecular or poly. Organic tft thinfilm transistor tft structure and operation geometri and requirements. Comparison of top and bottomcontact organic thin film transistors. Bottom gate bottom contact top contact top gate g insulator s d semiconductor substrate g insulator s d.
Meanwhile, in order to reduce the fabrication costs, simple fabrication conditions such as the. The gate electrode is immersed in the electrolyte and source and drain electrodes, isolated from the electrolyte, provide electrical contact to the channel figure1b. Highperformance bottomcontact organic thinfilm transistors based on benzod,d. Bottom gate top contact bgtc and bottom gate bottom contact bgbc. Contact resistance in organic transistors that use source. Hsiuchieh chang youjhih liang chiehyuan feng chiaming yeh jiachong ho chengchung lee mingchou chen. Pss to gold sourcedrain sd electrodes, thereby reducing contact. Article critical evaluation of organic thinfilm transistor models markus krammer 1, james w. In this study, transparent gadoped zno gzo films grown by magnetron sputtering were used as the sourcedrain sd electrodes of bottomcontact organic.
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