Increasing performance demands and shorter use lifetimes of consumer electronics have resulted in the rapid growth of electronic waste. Currently, consumer electronics are typically made with ...nondecomposable, nonbiocompatible, and sometimes even toxic materials, leading to serious ecological challenges worldwide. Here, we report an example of totally disintegrable and biocompatible semiconducting polymers for thin-film transistors. The polymer consists of reversible imine bonds and building blocks that can be easily decomposed under mild acidic conditions. In addition, an ultrathin (800-nm) biodegradable cellulose substrate with high chemical and thermal stability is developed. Coupled with iron electrodes, we have successfully fabricated fully disintegrable and biocompatible polymer transistors. Furthermore, disintegrable and biocompatible pseudo-complementary metal–oxide–semiconductor (CMOS) flexible circuits are demonstrated. These flexible circuits are ultrathin (<1 μm) and ultralightweight (∼2 g/m²) with low operating voltage (4 V), yielding potential applications of these disintegrable semiconducting polymers in low-cost, biocompatible, and ultralightweight transient electronics.
“Molecule‐framework” and “side‐chain” engineering is powerful for the design of high‐performance organic semiconductors. Based on 2DQTTs, the relationship between molecular structure, film ...microstructure, and charge‐transport property in organic thin‐film transistors (OTFTs) is studied. 2DQTT‐o‐B exhibits outstanding electron mobilities of 5.2 cm2 V–1 s–1, which is a record for air‐stable solution‐processable n‐channel small‐molecule OTFTs to date.
High-Performance Vertical Organic Transistors Kleemann, Hans; Günther, Alrun A.; Leo, Karl ...
Small (Weinheim an der Bergstrasse, Germany),
November 11, 2013, Letnik:
9, Številka:
21
Journal Article
Recenzirano
Vertical organic thin‐film transistors (VOTFTs) are promising devices to overcome the transconductance and cut‐off frequency restrictions of horizontal organic thin‐film transistors. The basic ...physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self‐assembly processes which impedes a future large‐area production. In this contribution, high‐performance vertical organic transistors comprising pentacene for p‐type operation and C60 for n‐type operation are presented. The static current–voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self‐assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high‐performance applications of organic transistors.
A novel architecture for high performance vertical organic transistors is presented. Using C60 and pentacene, an n‐ and p‐type transistor operation in these devices possessing a channel length of <100 μm is obtained. High transconductance values combined with the advantage of photolithographic integration will allow them to surpass the performance restrictions of planar transistor concepts.
This study investigates the low-frequency noise characteristics of the <inline-formula> <tex-math notation="LaTeX">{p} </tex-math></inline-formula>-type organic thin-film transistors (OTFTs) with ...dinaphtho2,3-b:2',3'-fthieno3,2-bthiophene (DNTT) by considering density-of-states (DOS). The OTFTs are fabricated with and without a self-assembled monolayer (SAM) on the SiO2 gate dielectrics. A significant reduction of 1/<inline-formula> <tex-math notation="LaTeX">{f} </tex-math></inline-formula> is observed in the OTFTs with SAM compared to those without SAM. Moreover, this reduction is more pronounced in the high drain current region, indicating that the excess noise is reduced due to the lower DOS resulting from the introduction of SAM.
In this study, organic thin‐film transistors (OTFTs) are investigated as a promising platform for cost‐effective, reconfigurable, and strong electronic physically unclonable functions (PUFs) for ...highly secure cryptography primitives. Simple spin‐casting of solution‐processable small‐molecule organic semiconductors forms unique and unclonable fingerprint thin films with randomly distributed polycrystalline structures ranging from nanoscale molecular orientations to microcrystalline orientations, which provides a stochastic entropy source of device‐to‐device variations for OTFT arrays. Blending organic semiconductors with polymer materials is a promising strategy to improve the reliability of OTFT‐based PUFs. Studies on the relationship between the phase‐separated polycrystalline microstructure of organic semiconductor/polymer blend films and PUF characteristics reveal that the 2D mosaic microcrystalline structure of organic semiconductors in the vertically phase‐separated trilayered structure enables the implementation of OTFT‐based PUFs that simultaneously satisfy the requirements of being unclonable and unpredictable, with reliable cryptographic properties. The inherent multiscale randomness of the crystalline structure allows random distribution in OTFT‐based PUFs even with various channel dimensions. The secret bit stream generated from the OTFT‐based PUF developed in this study is reconfigurable by simply changing the gate bias, demonstrating the potential to counter evolving security attack threats.
Organic thin‐film transistors are investigated as a promising platform for cost‐effective, reconfigurable, and strong electronic physically unclonable functions for highly secure cryptography primitives. 2D mosaic microcrystalline structure of organic semiconductors in the vertically phase‐separated polymer blend thin‐film enables the implementation of organic thin‐film transistors‐based physically unclonable functions that simultaneously satisfy the requirements of being unclonable and unpredictable, with reliable cryptographic properties.
Organic electrochemical transistors (OECTs) are devices with broad potential in bioelectronic sensing, circuits, and neuromorphic hardware. Their unique properties arise from the use of organic mixed ...ionic/electronic conductors (OMIECs) as the active channel. Typical OMIECs are linear polymers, where defined and controlled microstructure/morphology, and reliable characterization of transport and charging can be elusive. Semiconducting two‐dimensional polymers (2DPs) present a new avenue in OMIEC materials development, enabling electronic transport along with precise control of well‐defined channels ideal for ion transport/intercalation. To this end, a recently reported 2DP, TIIP, is synthesized and patterned at 10 µm resolution as the channel of a transistor. The TIIP films demonstrate textured microstructure and show semiconducting properties with accessible oxidation states. Operating in an aqueous electrolyte, the 2DP‐OECT exhibits a device‐scale hole mobility of 0.05 cm2 V–1 s–1 and a µC* figure of merit of 1.75 F cm–1 V–1 s–1. 2DP OMIECs thus offer new synthetic degrees of freedom to control OECT performance and may enable additional opportunities such as ion selectivity or improved stability through reduced morphological modulation during device operation.
Semiconducting two‐dimensional (2D) polymers feature synthetically tailored porosity and thus show both efficient electronic and ion transport. It is shown that two‐dimensional polymers (2DPs) can be patterned on the micrometer scale, and can be used as the active material for organic electrochemical transistors.
The development of transparent p‐type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit ...complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p‐type oxide semiconductors are reviewed, including ternary Cu‐bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence‐band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off‐state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p‐type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p‐type oxides still lag in performance behind their n‐type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p‐type oxide semiconductors are presented.
Recent progress in hole‐transporting (p‐type) oxide materials and devices is reviewed. Material design strategies to improve the transport properties of five classes of oxides are discussed, including ternary Cu‐bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. In addition, the performance of semiconductor electronic devices based on p‐type oxides is reviewed, including thin‐film transistors, CMOS inverters, p–n‐junction diodes, memory devices, gas sensors, and electrochromics. The recent successes and the hurdles that stand in the way of commercial adoption of p‐type semiconductors are discussed.
Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an ...important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n‐ and p‐type oxide based thin‐film transistors (TFT) is reviewed, with special emphasis on solution‐processed and p‐type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n‐type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution‐processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p‐type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n‐ and p‐type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n‐ and p‐type oxide transistors as well as the fabrication of CMOS devices with and on paper.
Transparent electronics is one of the most advanced science topics for a broad range of device applications. In this article an overview is presented of state‐of‐the‐art n‐ and p‐type oxides for TFTs and their integration, processed by physical vapor deposition and by solution processing techniques. Some of the most relevant emerging applications are also presented, including CMOS devices based on oxide TFTs fabricated on glass and even on paper.
For the large‐area fabrication of thin‐film transistors (TFTs), a new conjugated polymer poly9‐(1‐octylonoyl)‐9H‐carbazole‐2,7‐diyl is developed to harvest ultrahigh‐purity semiconducting ...single‐walled carbon nanotubes. Combined with spectral and nanodevice characterization, the purity is estimated up to 99.9%. High density and uniform network formed by dip‐coating process is liable to fabricate high‐performance TFTs on a wafer‐scale and the as‐fabricated TFTs exhibit a high degree of uniformity.
A facile polymer‐matrix‐mediated molecular self‐assembly of polymer semiconductors into highly crystalline orders for efficient charge transport in organic thin‐film transistors is demonstrated. ...Phenomenal enhancements in field‐effect mobility of about one order of magnitude and current on/off ratio of two to three orders of magnitude are realized with polyacrylonitrile‐incorporated polymer semiconductor compositions via solution deposition.
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