다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Organic thin-film transistors (OTFTs) have lived to see great improvements in recent years. This review presents new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of OTFTs. The shifted focus in research from novel chemical structures to fabrication technologies that optimize morphology and structural order is underscored by chapters on vacuum-deposited and solution-processed organic semiconducting films. Finally, progress in the growing field of the n-type OTFTs is discussed in ample detail. The Figure, showing a pentacene film edge on SiO2, illustrates the morphology issue.

Organic Thin Film Transistors for Large Area Electronics

During the past decade, enormous progress has been made in growing ultrathin organic films and multilayer structures with a wide range of exciting optoelectronic properties. This progress has been made possible by several important advances in our understanding of organic films and their modes of growth. Perhaps the single most important advance has been the use of ultrahigh vacuum (UHV) as a means to achieve, for the first time, monolayer control over the growth of organic thin films with extremely high chemical purity and structural precision.1-3 Such monolayer control has been possible for many years using well-known techniques such as Langmuir-Blodgett film deposition,4 and more recently, self-assembled monolayers from solution have also been achieved.5 However, ultrahighvacuum growth, sometimes referred to as organic molecular beam deposition (OMBD) or organic molecular beam epitaxy (OMBE), has the advantage of providing both layer thickness control and an atomically clean environment and substrate. When combined with the ability to perform in situ highresolution structural diagnostics of the films as they are being deposited, techniques such as OMBD have provided an entirely new prospect for understanding many of the fundamental structural and optoelectronic properties of ultrathin organic film systems. Since such systems are both of intrinsic as well as practical interest, substantial effort worldwide has been invested in attempting to grow and investigate the properties of such thin-film systems. This paper is a review of recent progress made in organic thin films grown in ultrahigh vacuum or using other vapor-phase deposition methods. We will describe the most important work which has been published in this field since the emergence of OMBD in the mid-1980s. Both the nature of thin-film growth and structural ordering will be discussed, as well as some of the more interesting consequences to the physical properties of such organic thin-film systems will be considered both from a theoretical as well as an experimental viewpoint. Indeed, it will 1793 Chem. Rev. 1997, 97, 1793−1896

Ultrathin Organic Films Grown by Organic Molecular Beam Deposition and Related Techniques.

The development of new organic semiconductors with improved performance in organic thin film transistors (OTFTs) is a major challenge for materials chemists. There is a particular need to develop air-stable n-channel (electron-conducting) organic semiconductors with performance comparable to that of p-channel (hole-conducting) materials, for organic electronics to realize the benefits of complementary circuit design, i.e., the ability to switch transistors with either positive or negative gate voltages. There have been significant advancements in the past five years. In terms of standard OTFT metrics such as the field effect mobility (μFET) and on-to-off current ratio (ION/IOFF), n-channel OTFTs have achieved performance comparable both to that of n-channel amorphous silicon TFTs and to that of the best reported p-channel (hole-conducting) OTFTs; however, issues of device stability linger. This review provides a detailed introduction to OTFTs, summarizes recent progress in the development of new n-channel...

Introduction to Organic Thin Film Transistors and Design of n-Channel Organic Semiconductors

The past couple of years have witnessed a remarkable burst in the development of organic field-effect transistors (OFETs), with a number of organic semiconductors surpassing the benchmark mobility of 10 cm2/(V s). In this perspective, we highlight some of the major milestones along the way to provide a historical view of OFET development, introduce the integrated molecular design concepts and process engineering approaches that lead to the current success, and identify the challenges ahead to make OFETs applicable in real applications.

Integrated materials design of organic semiconductors for field-effect transistors

Field-effect transistors based on intrinsic molecular semiconductors

In this review molecular field-effect transistors are described and compared with their gate-modified inorganic counterparts. The different processes involved in gas sensing are summarized. The advantages of transistors on resistors are demonstrated. The sensitivity of molecular field-effect transistors to strong oxidizing species, for example ozone, is detailed and compared with their sensitivity to humidity and volatile organic compounds. Application to ozone monitoring in urban atmospheres is also described.

/pdf/phthalocyanine-based-field-effect-transistors-as-gas-sensors-5bt18nw7ry.pdf

Phthalocyanine-based field-effect transistors as gas sensors

Electrical properties of rare earth bisphthalocyanine and bisnaphthalocyanine complexes

Solution processed thin films of an amphiphilic tris(phthalocyaninato) rare earth triple-decker complex, Eu2[Pc(15C5)4]2[Pc(OC10H21)8], have been prepared from three different methods: self-assembly (SA) annealed in solvent vapor, quasi-Langmuir–Shafer (QLS) and drop casting methods. In particular, we successfully developed a simple QLS process for fabricating ordered multilayers with a good thickness control. The films prepared from three different methods were characterized by a wide range of methods including electronic absorption spectra, IR, X-ray diffraction, atomic force microscopy (AFM), and current–voltage (I–V) measurements. J-type aggregates have been formed with the increasing degree of order of molecular stacking Cast < QLS < SA films. Moreover, the gas sensing behavior of the three types of films was investigated towards ozone in the 8–300 ppb range. Unexpectedly good sensitive, stable and reproducible responses to O3 gas are obtained for these kinds of ultra-thin solution processed films in a fast response/recovery cycle of only 1/4 min. The response of Eu2[Pc(15C5)4]2[Pc(OC10H21)8] films is linearly correlated to the ozone concentration. The interaction between the Eu2[Pc(15C5)4]2[Pc(OC10H21)8] films and different ozone concentrations was found to follow first-order kinetics. Strikingly, QLS films showed the most stable response and the largest average sensor response rate constant among the three types of films.

Facile approaches to build ordered amphiphilic tris(phthalocyaninato) europium triple-decker complex thin films and their comparative performances in ozone sensing

In this paper, we present a new sensor, which exhibits a sensitivity to ozone to less than 10 ppb. The device is a phthalocyanine-based field-effect transistor which is capable of working at room temperature. We describe a dynamic procedure, working out of the equilibrium state, to get rid of drift phenomena. A process where 2 min exposure alternates with 8 min static rest period leads, after a conditioning period, to a stable and reproducible signal. The response of the device (55 pA ppb −1  min −1 ) is linearly correlated to the ozone concentration in air, in the range 0–150 ppb. The use of a dynamic rest (flow of ozone free air) instead of a static rest reduces the duration of the recovery period, but is not necessary to achieve a good reproducibility.

Marcel Bouvet

Papers

Field-effect transistors based on intrinsic molecular semiconductors

Phthalocyanine-based field-effect transistors as gas sensors

Electrical properties of rare earth bisphthalocyanine and bisnaphthalocyanine complexes

Facile approaches to build ordered amphiphilic tris(phthalocyaninato) europium triple-decker complex thin films and their comparative performances in ozone sensing

Phthalocyanine-based field-effect transistor as ozone sensor