摘要 :
A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-- transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2 pm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter....
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A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-- transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2 pm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter.
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摘要 :
In this review paper, we present a comparative analysis of the electrochemical dissolution of III-V (InP, GaAs, GaN), II-VI (ZnSe, CdSe) and SiC semiconductor compounds. The resulting morphologies are discussed, including those of...
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In this review paper, we present a comparative analysis of the electrochemical dissolution of III-V (InP, GaAs, GaN), II-VI (ZnSe, CdSe) and SiC semiconductor compounds. The resulting morphologies are discussed, including those of porous layers and networks of low-dimensional structures such as nanowires, nanobelts, and nanomembranes. Self-organized phenomena in anodic etching are disclosed, leading to the formation of controlled porous patterns and quasi-ordered distribution of pores. Results of templated electrochemical deposition of metal nanowires, nanotubes and nanodots are summarized. Porosification of some compounds is shown to improve luminescence characteristics as well as to enhance photoconductivity, second harmonic generation and Terahertz emission. Possible applications of porous semiconductor compounds in various areas are discussed.
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beta-Ga2O3 is an emerging, ultra-wide bandgap (energy gap of 4.85 eV) transparent semiconducting oxide, which attracted recently much scientific and technological attention. Unique properties of that compound combined with its adv...
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beta-Ga2O3 is an emerging, ultra-wide bandgap (energy gap of 4.85 eV) transparent semiconducting oxide, which attracted recently much scientific and technological attention. Unique properties of that compound combined with its advanced development in growth and characterization place beta-Ga2O3 in the frontline of future applications in electronics (Schottky barrier diodes, field-effect transistors), optoelectronics (solar- and visible-blind photodetectors, flame detectors, light emitting diodes), and sensing systems (gas sensors, nuclear radiation detectors). A capability of growing large bulk single crystals directly from the melt and epilayers by a diversity of epitaxial techniques, as well as explored material properties and underlying physics, define a solid background for a device fabrication, which, indeed, has been boosted in recent years. This required, however, enormous efforts in different areas of science and technology that constitutes a chain linking together engineering, metrology and theory. The present review includes material preparation (bulk crystals, epi-layers, surfaces), an exploration of optical, electrical, thermal and mechanical properties, as well as device design/fabrication with resulted functionality suitable for different fields of applications. The review summarizes all of these aspects of beta-Ga2O3 at the research level that spans from the material preparation through characterization to final devices.
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Human health, environmental protection and safety are just a few examples of humankind's current main concerns, that drive the scientific community to develop sensors able to monitor precisely and provide alerts of possible harm i...
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Human health, environmental protection and safety are just a few examples of humankind's current main concerns, that drive the scientific community to develop sensors able to monitor precisely and provide alerts of possible harm in real time. Over the years, semiconductor metal oxide-based materials have been extensively employed as sensors in several applications. They are of particular interest at the nanometer scale, since it is widely known that a smaller crystallite size enhances a sensor's performance. Moreover, these materials are highly appealing as they can be produced by low-cost wet-chemical synthesis routes and are in general nontoxic, earth abundant and low cost. This manuscript extensively reviews the recent developments of nanostructured semiconductor metal oxide sensors ranging from gas to humidity sensors, including ultraviolet sensors and biosensors. Sensors based on zinc oxide (ZnO), titanium dioxide (TiO2), tungsten trioxide (WO3), copper oxide (CuO and Cu2O), tin oxide (SnO and SnO2) and vanadium oxide (VO2 and V2O5), either as nanoparticles or as continuous films or layers, are described. Their sensing properties are correlated to size, shape, presence of defects and doping elements, amongst other relevant parameters. Various techniques and methods of fabricating these materials are addressed. The review concludes with novel approaches for functionalization and future perspectives for sensor developments.
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