Explosive vapor sensor using poly (3-hexylthiophene) and CuII tetraphenylporphyrin composite based organic field effect transistors
31 Dec 2008-Applied Physics Letters (American Institute of Physics)-Vol. 93, Iss: 26, pp 263306
TL;DR: In this paper, organic field effect transistors based on poly(3-hexylthiophene) and CuII tetraphenylporphyrin composite were investigated as sensors for detection of vapors of nitro-based explosive compounds.
Abstract: Organic field effect transistors based on poly(3-hexylthiophene) and CuII tetraphenylporphyrin composite were investigated as sensors for detection of vapors of nitrobased explosive compounds, viz., 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), 2,4,6-trinitrotoluene (TNT), and dinitrobenzene, which are also strong oxidizing agents. Significant changes, suitable for sensor response, were observed in transistor “on” current (Ion) and conductance (S) after exposure. A similar device response was, however, not observed for oxidizing agents such as benzoquinone and benzophenone. The Fourier transform infrared spectrometry experiments supported the results, where exposure to RDX and TNT vapors resulted in a significant shift in IR peaks.
TL;DR: The history, current status of research, main challenges and prospects for functional OFETs are all discussed, in order to provide a comprehensive overview of this field.
Abstract: Functional organic field-effect transistors (OFETs) have attracted increasing attention in the past few years due to their wide variety of potential applications. Research on functional OFETs underpins future advances in organic electronics. In this review, different types of functional OFETs including organic phototransistors, organic memory FETs, organic light emitting FETs, sensors based on OFETs and other functional OFETs are introduced. In order to provide a comprehensive overview of this field, the history, current status of research, main challenges and prospects for functional OFETs are all discussed.
TL;DR: Progress to date suggests that OFETs may be integrated within a single substrate to function as an electronic mimic of human skin, which could enable a large range of sensing-related applications from novel prosthetics to robotic surgery.
Abstract: Skin is the body’s largest organ and is responsible for the transduction of a vast amount of information. This conformable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of an electronic material, inspired by the complexity of this organ is a tremendous, unrealized engineering challenge. However, the advent of carbon-based electronics may offer a potential solution to this long-standing problem.In this Account, we describe the use of an organic field-effect transistor (OFET) architecture to transduce mechanical and chemical stimuli into electrical signals. In developing this mimic of human skin, we thought of the sensory elements of the OFET as analogous to the various layers and constituents of skin. In this fashion, each layer of the OFET can be optimized to carry out a specific recognition function. The separation of multimodal sensing among the components of the OFET may be considered a “divide and...
TL;DR: This Review summarizes recent advances in the use of organic electronic materials for the detection of environmental chemicals, pressure, and light.
Abstract: Organic semiconductor films are susceptible to noncovalent interactions, trapping and doping, photoexcitation, and dimensional deformation. While these effects can be detrimental to the performance of conventional circuits, they can be harnessed, especially in field-effect architectures, to detect chemical and physical stimuli. This Review summarizes recent advances in the use of organic electronic materials for the detection of environmental chemicals, pressure, and light. The material features that are responsible for the transduction of the input signals to electronic information are discussed in detail.
TL;DR: In this paper, the authors provide a birds-eye view of the most promising classes of active layers as well as different device architectures and methods of fabrication, and strategies for interfacing bio components with organic or carbon nano-structured electronic active layers.
Abstract: Bio-sensing represents one of the most attractive applications of carbon material based electronic devices; nevertheless, the complete integration of bioactive transducing elements still represents a major challenge, particularly in terms of preserving biological function and specificity while maintaining the sensor's electronic performance. This review highlights recent advances in the realization of field-effect transistor (FET) based sensors that comprise a bio-receptor within the FET channel. A birds-eye view will be provided of the most promising classes of active layers as well as different device architectures and methods of fabrication. Finally, strategies for interfacing bio-components with organic or carbon nano-structured electronic active layers are reported.
TL;DR: This review will briefly discuss some of the methods for creating these multi-material sensor platforms and the advances enabled by this design approach.
Abstract: Label-free sensors based on electrical, mechanical and optical transduction methods have potential applications in numerous areas of society, ranging from healthcare to environmental monitoring. Initial research in the field focused on the development and optimization of various sensor platforms fabricated from a single material system, such as fiber-based optical sensors and silicon nanowire-based electrical sensors. However, more recent research efforts have explored designing sensors fabricated from multiple materials. For example, synthetic materials and/or biomaterials can also be added to the sensor to improve its response toward analytes of interest. By leveraging the properties of the different material systems, these hybrid sensing devices can have significantly improved performance over their single-material counterparts (better sensitivity, specificity, signal to noise, and/or detection limits). This review will briefly discuss some of the methods for creating these multi-material sensor platforms and the advances enabled by this design approach.
01 Apr 1985
TL;DR: In this paper, the transmission coefficient of a symmetric resonance tunneling diode has been derived for a Symmetric Resonant-Tunneling Diode, and it has been shown that it can be computed in terms of the Density of States in Semiconductor.
Abstract: Preface. Introduction. PART I: SEMICONDUCTOR PHYSICS. Energy Bands and Carrier Concentration in Thermal Equilibrium. Carrier Transport Phenomena. PART II: SEMICONDUCTOR DEVICES. p-n Junction. Bipolar Transistor and Related Devices. MOSFET and Related Devices. MESFET and Related Devices. Microwave Diodes, Quantum-Effect, and Hot-Electron Devices. Photonic Devices. PART III: SEMICONDUCTOR TECHNOLOGY. Crystal Growth and Epitaxy. Film Formation. Lithography and Etching. Impurity Doping. Integrated Devices. Appendix A: List of Symbols. Appendix B: International Systems of Units (SI Units). Appendix C: Unit Prefixes. Appendix D: Greek Alphabet. Appendix E: Physical Constants. Appendix F: Properties of Important Element and Binary Compound Semiconductors at 300 K. Appendix G: Properties of Si and GaAs at 300 K. Appendix H: Derivation of the Density of States in Semiconductor. Appendix I: Derivation of Recombination Rate for Indirect Recombination. Appendix J: Calculation of the Transmission Coefficient for a Symmetric Resonant-Tunneling Diode. Appendix K: Basic Kinetic Theory of Gases. Appendix L: Answers to Selected Problems. Index.
TL;DR: In this article, a new synthetic strategy for preparing tetraphenylporphyrins is presented, which should greatly expand synthetic entries into porphyrin-containing model systems, and is complementary to the Adler-Longo procedure.
Abstract: We present a new synthetic strategy for preparing tetraphenylporphyrins that should greatly expand synthetic entries into porphyrin containing model systems. Pyrrole and the desired benzaldehyde react reversibly at room temperature with trace acid catalysis to form the cyclic tetraphenylporphyrinogen at thermodynamic equilibrium. An oxidant is then added to irreversibly convert the porphyrinogen to the porphyrin. The greater stability of the cyclic porphyrinogen over the open-chain polypyrrylmethanes occurs when the reaction is performed at moderate dilution (10-2 M). The reaction at high dilution or high concentration affords a negligible yield of the cyclic porphyrinogen. Porphyrinogen exchange reactions provide proof of equilibrium. This methodology is complementary to the Adler-Longo procedure, allowing small quantities of porphyrins to be prepared from sensitive aldehydes in 30-40% yield without difficult purification problems. This methodology is also extended to the preparation of meso-tetraalkylporphyrins and one hybrid porphyrin containing both aryl and alkyl substituents. The mild reaction conditions and convenience of this method permit consideration of new design strategies in preparing complex porphyrins.
TL;DR: In this paper, the synthesis, spectroscopy, and fluorescence quenching behavior of pentiptycene-derived phenyleneethynylene polymers, 1−3, are reported.
Abstract: The synthesis, spectroscopy, and fluorescence quenching behavior of pentiptycene-derived phenyleneethynylene polymers, 1−3, are reported. The incorporation of rigid three-dimensional pentiptycene moieties into conjugated polymer backbones offers several design advantages for solid-state (thin film) fluorescent sensory materials. First, they prevent π-stacking of the polymer backbones and thereby maintain high fluorescence quantum yields and spectroscopic stability in thin films. Second, reduced interpolymer interactions dramatically enhance the solubility of polymers 1−3 relative to other poly(phenyleneethynylenes). Third, the cavities generated between adjacent polymers are sufficiently large to allow diffusion of small organic molecules into the films. These advantages are apparent from comparisons of the spectroscopic and fluorescence quenching behavior of 1−3 to a related planar electron-rich polymer 4. The fluorescence attenuation (quenching) of polymer films upon exposure to analytes depends on seve...
TL;DR: In this paper, the first solid-state field-effect transistor has been fabricated utilizing a film of an organic macromolecule, polythiophene, as a semiconductor.
Abstract: The first solid‐state field‐effect transistor has been fabricated utilizing a film of an organic macromolecule, polythiophene, as a semiconductor. The device characteristics have been optimized by controlling the doping levels of the polymer. The device is a normally off type and the source (drain) current can be modulated by a factor of 102–103 by varying the gate voltage. The carrier mobility and the transconductance have also been determined to be ∼10−5 cm2/V s and 3 nS, respectively, by means of electrical measurements.
TL;DR: In this paper, a field effect transistor structure was used to study the transport properties of poly(3−hexylthiophene) and showed that the field effect mobility was 10−5−10−4 cm2/V
Abstract: A field‐effect transistor structure is used to study the transport properties of the soluble conductive polymer, poly(3‐hexylthiophene). We have measured conductance, mobility, and carrier concentration in undoped polymer thin films. The field‐effect mobility was found to be 10−5–10−4 cm2/V s at room temperature. The mobility decreases with increased temperature. The change is only partly reversible. Possible transport models are discussed.