Experimental techniques for the fabrication and characterization of organic thin films for field-effect transistors.
About: This article is published in Chemical Reviews.The article was published on 2011-03-14. It has received 234 citations till now.
Citations
More filters
TL;DR: The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials and highlights the capabilities of various experimental techniques for characterization, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field.
Abstract: Organic (opto)electronic materials have received considerable attention due to their applications in thin-film-transistors, light-emitting diodes, solar cells, sensors, photorefractive devices, and many others. The technological promises include low cost of these materials and the possibility of their room-temperature deposition from solution on large-area and/or flexible substrates. The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials. The focus of the review is on photoinduced processes and on electronic properties important for optoelectronic applications relying on charge carrier photogeneration. Additionally, it highlights the capabilities of various experimental techniques for characterization of these materials, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field. The properties of materials based both on small molecules and on conjug...
995 citations
TL;DR: A review of roll-to-roll (R2R) compatible applications for thin-film transistors can be found in this article, where the current status of R2R application within some of the existing research fields such as organic photovoltaics, organic thin film transistors, light-emitting diodes, polymer electrolyte membrane fuel cells and electrochromic devices.
Abstract: With the prospect of extremely fast manufacture of very low cost devices, organic electronics prepared by thin film processing techniques that are compatible with roll-to-roll (R2R) methods are presently receiving an increasing interest. Several technologies using organic thin films are at the point, where transfer from the laboratory to a more production-oriented environment is within reach. In this review, we aim at giving an overview of some of the R2R-compatible techniques that can be used in such a transfer, as well the current status of R2R application within some of the existing research fields such as organic photovoltaics, organic thin film transistors, light-emitting diodes, polymer electrolyte membrane fuel cells, and electrochromic devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
936 citations
TL;DR: Two donor-acceptor (D-A) copolymer PDVTs based on diketopyrrolopyrole and (E)-2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) units are synthesized for solution-processed field-effect transistors (FETs) to strengthen the coplanarity of the polymer backbone.
Abstract: Two donor-acceptor (D-A) copolymer PDVTs based on diketopyrrolopyrole and (E)-2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) units are synthesized for solution-processed field-effect transistors (FETs). The highly π-extended TVT units strengthen the coplanarity of the polymer backbone. FETs based on PDVTs show high mobilities above 2.0 cm(2) V(-1) s(-1) with a current on/off ratio of 10(5)-10(7) , high shelf storage, and operation stability.
718 citations
TL;DR: It is expected that this systematic analysis of photoresponse materials and devices could be a guide for the better understanding of structure-property relationships of organic materials and provide key clues for the fabrication of high performance organic optoelectronic devices.
Abstract: Organic photoresponse materials and devices are critically important to organic optoelectronics and energy crises. The activities of photoresponse in organic materials can be summarized in three effects, photoconductive, photovoltaic and optical memory effects. Correspondingly, devices based on the three effects can be divided into (i) photoconductive devices such as photodetectors, photoreceptors, photoswitches and phototransistors, (ii) photovoltaic devices such as organic solar cells, and (iii) optical data storage devices. It is expected that this systematic analysis of photoresponse materials and devices could be a guide for the better understanding of structure–property relationships of organic materials and provide key clues for the fabrication of high performance organic optoelectronic devices, the integration of them in circuits and the application of them in renewable green energy strategies (critical review, 452 references).
550 citations
TL;DR: This review provides a comprehensive overview of the molecular packing, morphology and charge transport features of organic semiconductor crystals, the control of crystallization for achieving high quality crystals and the device physics in the three main applications.
Abstract: Organic semiconductors have attracted a lot of attention since the discovery of highly doped conductive polymers, due to the potential application in field-effect transistors (OFETs), light-emitting diodes (OLEDs) and photovoltaic cells (OPVs). Single crystals of organic semiconductors are particularly intriguing because they are free of grain boundaries and have long-range periodic order as well as minimal traps and defects. Hence, organic semiconductor crystals provide a powerful tool for revealing the intrinsic properties, examining the structure–property relationships, demonstrating the important factors for high performance devices and uncovering fundamental physics in organic semiconductors. This review provides a comprehensive overview of the molecular packing, morphology and charge transport features of organic semiconductor crystals, the control of crystallization for achieving high quality crystals and the device physics in the three main applications. We hope that this comprehensive summary can give a clear picture of the state-of-art status and guide future work in this area.
537 citations
References
More filters
TL;DR: In this article, the authors used thin-film, field effect transistor structures to probe the transport properties of the ordered microcrystalline domains in the conjugated polymer poly(3-hexylthiophene), P3HT.
Abstract: Self-organization in many solution-processed, semiconducting conjugated polymers results in complex microstructures, in which ordered microcrystalline domains are embedded in an amorphous matrix1. This has important consequences for electrical properties of these materials: charge transport is usually limited by the most difficult hopping processes and is therefore dominated by the disordered matrix, resulting in low charge-carrier mobilities2 (⩽10-5 cm2 V-1 s-1). Here we use thin-film, field-effect transistor structures to probe the transport properties of the ordered microcrystalline domains in the conjugated polymer poly(3-hexylthiophene), P3HT. Self-organization in P3HT results in a lamella structure with two-dimensional conjugated sheets formed by interchain stacking. We find that, depending on processing conditions, the lamellae can adopt two different orientations—parallel and normal to the substrate—the mobilities of which differ by more than a factor of 100, and can reach values as high as 0.1 cm2 V-1 s-1 (refs 3, 4). Optical spectroscopy of the field-induced charge, combined with the mobility anisotropy, reveals the two-dimensional interchain character of the polaronic charge carriers, which exhibit lower relaxation energies than the corresponding radical cations on isolated one-dimensional chains. The possibility of achieving high mobilities via two-dimensional transport in self-organized conjugated lamellae is important for applications of polymer transistors in logic circuits5 and active-matrix displays4,6.
4,306 citations
TL;DR: It is shown that the use of substrate surface energy patterning to direct the flow of water-based conducting polymer inkjet droplets enables high-resolution definition of practical channel lengths of 5 micrometers, and high mobilities were achieved.
Abstract: Direct printing of functional electronic materials may provide a new route to low-cost fabrication of integrated circuits. However, to be useful it must allow continuous manufacturing of all circuit components by successive solution deposition and printing steps in the same environment. We demonstrate direct inkjet printing of complete transistor circuits, including via-hole interconnections based on solution-processed polymer conductors, insulators, and self-organizing semiconductors. We show that the use of substrate surface energy patterning to direct the flow of water-based conducting polymer inkjet droplets enables high-resolution definition of practical channel lengths of 5 micrometers. High mobilities of 0.02 square centimeters per volt second and on-off current switching ratios of 10 5 were achieved.
3,190 citations
2,982 citations
TL;DR: A highly soluble and printable n-channel polymer exhibiting unprecedented OTFT characteristics under ambient conditions in combination with Au contacts and various polymeric dielectrics is reported and all-printed polymeric complementary inverters have been demonstrated.
Abstract: Printed electronics is a revolutionary technology aimed at unconventional electronic device manufacture on plastic foils, and will probably rely on polymeric semiconductors for organic thin-film transistor (OTFT) fabrication. In addition to having excellent charge-transport characteristics in ambient conditions, such materials must meet other key requirements, such as chemical stability, large solubility in common solvents, and inexpensive solution and/or low-temperature processing. Furthermore, compatibility of both p-channel (hole-transporting) and n-channel (electron-transporting) semiconductors with a single combination of gate dielectric and contact materials is highly desirable to enable powerful complementary circuit technologies, where p- and n-channel OTFTs operate in concert. Polymeric complementary circuits operating in ambient conditions are currently difficult to realize: although excellent p-channel polymers are widely available, the achievement of high-performance n-channel polymers is more challenging. Here we report a highly soluble ( approximately 60 g l(-1)) and printable n-channel polymer exhibiting unprecedented OTFT characteristics (electron mobilities up to approximately 0.45-0.85 cm(2) V(-1) s(-1)) under ambient conditions in combination with Au contacts and various polymeric dielectrics. Several top-gate OTFTs on plastic substrates were fabricated with the semiconductor-dielectric layers deposited by spin-coating as well as by gravure, flexographic and inkjet printing, demonstrating great processing versatility. Finally, all-printed polymeric complementary inverters (with gain 25-65) have been demonstrated.
2,769 citations
2,346 citations