Search results for "Semiconductor"
showing 10 items of 974 documents
Latest Developments and Results of Radiation Tolerance CMOS Sensors with Small Collection Electrodes
2020
The development of radiation hard Depleted Monolithic Active Pixel Sensors (DMAPS) targets the replacement of hybrid pixel detectors to meet radiation hardness requirements of at least 1.5e16 1 MeV neq/cm2 for the HL-LHC and beyond. DMAPS were designed and tested in the TJ180 nm TowerJazz CMOS imaging technology with small electrodes pixel designs. This technology reduces costs and provides granularity of 36.4x36.4 um2 with low power operation (1 uW/pixel), low noise of ENC < 20 e-, a small collection electrode (3 um) and fast signal response within 25 ns bunch crossing. This contribution will present the latest developments after the MALTA and Mini-MALTA sensors. It will illustrate the imp…
Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning
2013
Selecting and tuning modes are useful in ultrasonic guided wave non-destructive testing (NDT) since certain modes at various center frequencies are sensitive to specific types of defects. Ideally one should be able to select both the mode and the center frequency of the launched waves. We demonstrated that an affordable laser diode array can selectively launch either the S0 or A0 ultrasonic wave mode at a chosen center frequency into a polymer plate. A fiber-coupled diode array (4 elements) illuminated a 2 mm thick acrylic plate. A predetermined time delay matching the selected mode and frequency was employed between the output of the elements. The generated ultrasound was detected by a 215…
Signal processing in photonic crystals and nanostructures
2006
International audience; Optical devices employing photonic crystals and novel nanostructure materials may exhibit useful properties for applications to all-optical signal processing. In this work we analyze as a first example four-wave mixing of polarized beams in photonic crystal fibers. We show that by properly tuning the pump wavelength and the linear dispersion properties of the fiber one may obtain broadband parametric amplification and frequency conversion. Next we consider the in-line periodic amplification of short optical pulses by means of quantum-dot semiconductor optical amplifiers. We show by numerical simulations that pattern-free amplification of a 40 Gbit/s soliton signal at…
Atomic layer deposition of AlN from AlCl3 using NH3 and Ar/NH3 plasma
2018
The atomic layer deposition (ALD) of AlN from AlCl3 was investigated using a thermal process with NH3 and a plasma-enhanced (PE)ALD process with Ar/NH3 plasma. The growth was limited in the thermal process by the low reactivity of NH3, and impractically long pulses were required to reach saturation. Despite the plasma activation, the growth per cycle in the PEALD process was lower than that in the thermal process (0.4A ° vs 0.7A ° ). However, the plasma process resulted in a lower concentration of impurities in the films compared to the thermal process. Both the thermal and plasma processes yielded crystalline films; however, the degree of crystallinity was higher in the plasma process. The…
Unravelling the Intertwined Atomic and Bulk Nature of Localised Excitons by Attosecond Spectroscopy
2021
The electro-optical properties of most semiconductors and insulators of technological interest are dominated by the presence of electron-hole quasi-particles, called excitons. The manipulation of excitons in dielectrics has recently received great attention, with possible applications in different fields including optoelectronics and photonics. Here, we apply attosecond transient reflection spectroscopy in a sequential two-foci geometry and observe sub-femtosecond dynamics of a core-level exciton in bulk MgF2 single crystals. Furthermore, we access absolute phase delays, which allow for an unambiguous comparison with theoretical calculations. Our results show that excitons surprisingly exhi…
New charge transfer salts of two organic π-donors of the tetrathiafulvalene type with the paramagnetic [Cr(NCS)6]3- anion
2003
cited By 9; International audience; The electrochemical combination of the paramagnetic anion [Cr(NCS)6]3- with the organic π-donors bis(ethylenedithio)tetrathiafulvalene (ET) and 4,5-bis(2-hydroxyethylthio) -4′,5′-ethylenedithiotetrathiafulvalene (DHET-EDTTTF) leads to two new radical cation salts, namely (ET)4 [Cr(NCS 6]·PhCN 1 and (DHET-EDTTTF)2 (NEt4)[Cr(NCS)6] 2. Both have been characterized by X-ray crystallography, magnetic and resistivity measurements. The structure of 1 consists of alternating inorganic layers generated by the anions and organic layers in which the PhCN molecules are inserted; the organic sub-lattice is built up from four different ET units, three of them with a ch…
Blue Emitting Organic Light Emitting Diodes
2019
Organic light emitting diodes (OLEDs) [1] can be fabricated on a range of materials such as glass, silicon or flexible plastic substrates. This can be exploited for the realization of integrated OLED-based fluorescence chemical sensors [2] and microfluidic systems [3] for application in areas such as biotechnology, life sciences, pharmaceuticals, public health and defense. These devices hold promises to be cost effective, ultra-compact (including the possibility to be fabricated into large bidimensional arrays), and capable to handle smaller sample volumes in order to achieve high throughput. Blue light is advantageous because it is strongly absorbed by most sensing molecules attached to bi…
Thin Film CIGS Solar Cells, Photovoltaic Modules, and the Problems of Modeling
2013
Starting from the results regarding a nonvacuum technique to fabricate CIGS thin films for solar cells by means of single-step electrodeposition, we focus on the methodological problems of modeling at cell structure and photovoltaic module levels. As a matter of fact, electrodeposition is known as a practical alternative to costly vacuum-based technologies for semiconductor processing in the photovoltaic device sector, but it can lead to quite different structural and electrical properties. For this reason, a greater effort is required to ensure that the perspectives of the electrical engineer and the material scientist are given an opportunity for a closer comparison and a common language.…
Semiconductors: Growth and Characterization
2018
Semiconducting materials are widely used in several applications such as photonics, photovoltaics, electronics and thermoelectrics, because of their optical and electro-optical features. The fundamental and technological importance of these materials is due to the unique physical and chemical properties. Over the years, numerous methods have been developed for the synthesis of high efficient semiconductors. Besides, a variety of approach and characterization methods have been used to study the numerous and fascinating properties of the semiconducting materials. This book collects new developments about semiconductors, from the fundamental issues to the synthesis and applications. Special at…
Heavy-Ion-Induced Degradation in SiC Schottky Diodes : Incident Angle and Energy Deposition Dependence
2017
Heavy-ion-induced degradation in the reverse leakage current of SiC Schottky power diodes exhibits a strong dependence on the ion angle of incidence. This effect is studied experimentally for several different bias voltages applied during heavy-ion exposure. In addition, TCAD simulations are used to give insight on the physical mechanisms involved. peerReviewed