Aza-boron-dipyromethene (aza-BODIPY) derivatives 1-6 were synthesized for the first time by employing the palladium catalyzed Suzuki-Miyaura coupling on dibromo-aza-BODIPY. Photophysical and ...electrochemical properties of these compounds were studied in solution. Absorption and emission maxima were observed in the near-infrared (NIR) region and were found to extend up to 754 and 751 nm, respectively. NIR fluorescence quantum yields in chloroform were as high as 0.45. Optical band gaps were measured from the onset of absorption spectra in thin films and were found to be low (ca. 1.2-1.4 eV). Electrochemical studies provided insight into the reduction potentials of these compounds and consequently the electron affinity (EA). High electron affinity (ca. 4.5) was observed for these dyes. NIR absorption and emission, good quantum yield, and high electron affinity of these compounds promise their applications in microscope imaging and optoelectronic devices, mainly in solar cells and field-effect transistors. PUBLICATION ABSTRACT
Studies on printable semiconductors and technologies have increased rapidly over recent decades, pioneering novel applications in many fields, such as energy, sensing, logic circuits, and information ...displays. The newest display technologies are already turning to metal oxide semiconductors, i.e., indium gallium zinc oxide, for the improvements needed to drive active matrix organic light‐emitting diodes. Convenience and portability will be realized with flexible and wearable displays in the future. This report summarizes recent progress on the development of solution‐processed thin film transistors, especially those deposited at low temperatures for next‐generation flexible smart displays. The first part provides an overview on the history and current status of displays. Then, recent advances in state‐of‐the‐art solution‐processed transistors based on different semiconductors are presented, including metal oxides, organic materials, perovskites, and carbon nanotubes. Finally, conclusions are drawn and the remaining challenges and future perspectives are discussed.
Semiconductor evolution has greatly promoted the development of high‐end displays over the past decades. Benefiting from the unique characteristics of low‐cost solution routes, recent progress in the development of solution‐processed thin film transistors (metal oxides, organics, carbon nanotubes, and perovskite) and their applications in next‐generation flexible smart displays are summarized. The challenges and prospectives for further development are also highlighted.
The magnetoelectric (ME) effect, the phenomenon of inducing magnetization by application of an electric field or vice versa, holds great promise for magnetic sensing and switching applications. ...Studies of the ME effect have so far focused on the control of the electron spin degree of freedom (DOF) in materials such as multiferroics and conventional semiconductors. Here, we report a new form of the ME effect based on the valley DOF in two-dimensional Dirac materials. By breaking the three-fold rotational symmetry in single-layer MoS
via a uniaxial stress, we have demonstrated the pure electrical generation of valley magnetization in this material, and its direct imaging by Kerr rotation microscopy. The observed out-of-plane magnetization is independent of in-plane magnetic field, linearly proportional to the in-plane current density, and optimized when the current is orthogonal to the strain-induced piezoelectric field. These results are fully consistent with a theoretical model of valley magnetoelectricity driven by Berry curvature effects. Furthermore, the effect persists at room temperature, opening possibilities for practical valleytronic devices.
Jo Briault, managing director of Pet-ID Microchips, said: 'We want to offer a "try before you buy" to practices so they can really experience the ease of implantation and quality of the chips and ...choose the options that are right for them.'
In this study, polyethylene glycol (PEG)-coated Gd-doped zinc oxide (ZnO) nanoparticles were prepared by the one-pot solvothermal method. X-ray diffraction measurements indicated that all the ...prepared samples had a wurtzite structure. The size of the nanoparticles could be controlled to be approximately 15 nm. Magnetization measurements using a SQUID magnetometer indicated that the saturation magnetization was enhanced by Gd doping. Local structure analysis by X-ray absorption fine structure measurements revealed the presence of oxygen vacancies, suggesting that this is related to the increased magnetization of the prepared samples.
Small-molecule organic semiconductors have displayed remarkable electronic properties with a multitude of π-conjugated structures developed and fine-tuned over recent years to afford highly efficient ...hole- and electron-transporting materials. Already making a significant impact on organic electronic applications including organic field-effect transistors and solar cells, this class of materials is also now naturally being considered for the emerging field of organic bioelectronics. In efforts aimed at identifying and developing (semi)conducting materials for bioelectronic applications, particular attention has been placed on materials displaying mixed ionic and electronic conduction to interface efficiently with the inherently ionic biological world. Such mixed conductors are conveniently evaluated using an organic electrochemical transistor, which further presents itself as an ideal bioelectronic device for transducing biological signals into electrical signals. Here, we review recent literature relevant for the design of small-molecule mixed ionic and electronic conductors. We assess important classes of p- and n-type small-molecule semiconductors, consider structural modifications relevant for mixed conduction and for specific interactions with ionic species, and discuss the outlook of small-molecule semiconductors in the context of organic bioelectronics.
Due to its significant applications in many relevant fields, light detection in the solar‐blind deep‐ultraviolet (DUV) wavelength region is a subject of great interest for both scientific and ...industrial communities. The rapid advances in preparing high‐quality ultrawide‐bandgap (UWBG) semiconductors have enabled the realization of various high‐performance DUV photodetectors (DUVPDs) with different geometries, which provide an avenue for circumventing numerous disadvantages in traditional DUV detectors. This article presents a comprehensive review of the applications of inorganic UWBG semiconductors for solar‐blind DUV light detection in the past several decades. Different kinds of DUVPDs, which are based on varied UWBG semiconductors including Ga2O3, MgxZn1−xO, III‐nitride compounds (AlxGa1−xN/AlN and BN), diamond, etc., and operate on different working principles, are introduced and discussed systematically. Some emerging techniques to optimize device performance are addressed as well. Finally, the existing techniques are summarized and future challenges are proposed in order to shed light on development in this critical research field.
Recent advances in developing solar‐blind deep ultraviolet light (DUV) photodetectors based on various inorganic ultrawide‐bandgap semiconductors are reviewed, such as Ga2O3, MgxZn1−xO, III‐nitride compounds (AlxGa1−xN/AlN and BN), and diamonds.
Engineering semiconductor devices requires an understanding of charge carrier mobility. Typically, mobilities are estimated using Hall effect and electrical resistivity meausrements, which are are ...routinely performed at room temperature and below, in materials with mobilities greater than 1 cm2 V‐1 s‐1. With the availability of combined Seebeck coefficient and electrical resistivity measurement systems, it is now easy to measure the weighted mobility (electron mobility weighted by the density of electronic states). A simple method to calculate the weighted mobility from Seebeck coefficient and electrical resistivity measurements is introduced, which gives good results at room temperature and above, and for mobilities as low as 10−3 cm2 V‐1 s‐1,
μw=331cm2Vs(mΩ cmρ) (T300 K)−3/2 exp |S|kB/e−21+exp−5(|S|kB/e−1) +3π2|S|kB/e1+exp5(|S|kB/e−1) Here, μw is the weighted mobility, ρ is the electrical resistivity measured in mΩ cm, T is the absolute temperature in K, S is the Seebeck coefficient, and kB/e = 86.3 µV K–1. Weighted mobility analysis can elucidate the electronic structure and scattering mechanisms in materials and is particularly helpful in understanding and optimizing thermoelectric systems.
The weighted mobility, easily computed from measurements of the Seebeck coefficient and electrical resistivity, is an accurate measure of the charge carrier mobility and effective mass. It is even more sensitive than measurements of the Hall effect for revealing electron transport mechanisms in complex materials ranging from metals, semiconductors, and conducting polymers.
For GaN compound semiconductors, the position of dislocations was confirmed by STEM, and the elemental distribution was clarified by APT. From the results of APT, cluster segregation of Mg and In was ...observed on the dislocation, and it could be considered that they were diffused along the dislocations.
This paper presents an ultra-low power batteryless energy harvesting body sensor node (BSN) SoC fabricated in a commercial 130 nm CMOS technology capable of acquiring, processing, and transmitting ...electrocardiogram (ECG), electromyogram (EMG), and electroencephalogram (EEG) data. This SoC utilizes recent advances in energy harvesting, dynamic power management, low voltage boost circuits, bio-signal front-ends, subthreshold processing, and RF transmitter circuit topologies. The SoC is designed so the integration and interaction of circuit blocks accomplish an integrated, flexible, and reconfigurable wireless BSN SoC capable of autonomous power management and operation from harvested power, thus prolonging the node lifetime indefinitely. The chip performs ECG heart rate extraction and atrial fibrillation detection while only consuming 19 Formula OmittedW, running solely on harvested energy. This chip is the first wireless BSN powered solely from a thermoelectric harvester and/or RF power and has lower power, lower minimum supply voltage (30 mV), and more complete system integration than previously reported wireless BSN SoCs.
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