Search results for "schottky"
showing 10 items of 109 documents
Incident angle effect on heavy ion induced reverse leakage current in SiC Schottky diodes
2016
Heavy-ion induced degradation in the reverse leakage current of SiC Schottky power diodes shows distinct dependence on the angle of incidence. TCAD simulations have been used to study the physical mechanisms involved.
The Structural Disorder and Lattice Stability of (Ba,Sr)(Co,Fe)O3 Complex Perovskites
2011
The structural disorder and lattice stability of complex perovskite (Ba,Sr)(Co,Fe)O3, a promising cathode material for solid oxide fuel cells and oxygen permeation membranes, is explored by means of first principles DFT calculations. It is predicted that Ba and Sr ions easily exchange their lattice positions (A-cation disorder) similarly to Co and Fe ions (B-cation disorder). The cation antisite defects (exchange of A- and B-type cations) also have the low formation energy. The BSCF is predicted to exist in an equilibrium mixture of several phases and can decompose exothermically into the Ba- and Co-rich hexagonal (Ba,Sr)CoO3 and Sr- and Fe-rich cubic (Ba,Sr)FeO3 perovskites.
Ambipolar MoS2 Transistors by Nanoscale Tailoring of Schottky Barrier Using Oxygen Plasma Functionalization
2017
One of the main challenges to exploit molybdenum disulfide (MoS2) potentialities for the next-generation complementary metal oxide semiconductor (CMOS) technology is the realization of p-type or ambipolar field-effect transistors (FETs). Hole transport in MoS2 FETs is typically hampered by the high Schottky barrier height (SBH) for holes at source/drain contacts, due to the Fermi level pinning close to the conduction band. In this work, we show that the SBH of multilayer MoS2 surface can be tailored at nanoscale using soft O-2 plasma treatments. The morphological, chemical, and electrical modifications of MoS2 surface under different plasma conditions were investigated by several microscopi…
High Performance Solar Blind Detectors based on AlGaN grown by MBE and MOCVD
2004
ABSTRACTSolar blind detectors based on AlGaN grown by Molecular Beam Epitaxy and Metal Organic Vapor Phase Epitaxy have been fabricated and characterized. Metal Semiconductor Metal (MSM) detectors and vertical Schottky detectors have been realized, with a design that allows back side illumination. The growth was optimized in order to improve the layer quality, avoid crack formation, and provide the best detector performance. The technological process was also optimized in order to reduce the dark currents and improve the spectral rejection ratio, which is a key factor for solar blind detection. As a result, a rejection ratio of 5 decades between the UV (below 300 nm) and 400 nm, and a steep…
Responsivity measurements of 4H-SiC Schottky photodiodes for UV light monitoring
2014
We report on the design and the electro-optical characterization of a novel class of 4H-SiC vertical Schottky UV detectors, based on the pinch-off surface effect and obtained employing Ni2Si interdigitated strips. We have measured, in dark conditions, the forward and reverse I–V characteristics as a function of the temperature and the C–V characteristics. Responsivity measurements of the devices, as a function of the wavelength (in the 200 – 400 nm range), of the package temperature and of the applied reverse bias are reported. We compared devices featured by different strip pitch size, and found that the 10 μm device pitch exhibits the best results, being the best compromise in terms of fu…
Amorphous semiconductor—electrolyte junction. Impedance study on the a-Nb2 O5—electrolyte junction
1990
Abstract A systematic study of the impedance behaviour of the anodic niobium oxide film/aqueous electrolyte interface was carried out using the lock-in technique at different signal frequencies. The dependence of both components of the impedance on the electrode potential and on frequency is analysed by taking into account the amorphous nature of the films. The lack of long-range order in these oxide layers modifies the physical picture in respect to the case of single crystal semiconductors. A new equivalent circuit has been assumed, based on recent theory of an amorphous semiconductor Schottky barrier. Such a new approach allows the characterization of the interface and the determination …
High Temperature SiC Blocking Diodes for Solar Array
2009
This paper presents the results of an experimental investigation of the performance of 300V-5A Silicon Carbide Ni and W Schottky diode operating in the range between -170°C to 270°C. We have developed these diodes as blocking diodes, for solar cell array protection in order to fulfill the BepiColombo mission specifications. An electro-thermal characterization has been performed taking into account the harsh condition of the mission (high temperature range and electrical stress). The destructive and non-destructive tests have assured that the designed SiC diodes are able to support the electro-thermal limits. A reliability test has also been performed to investigate the stability of forward …
Integrated SINIS refrigerators for efficient cooling of cryogenic detectors
2002
In this paper we report recent results obtained with large area superconductor-insulator-normal metal-insulator-superconductor tunnel junction coolers. With the devices we have successfully demonstrated electronic cooling from 260 mK to 80 mK with a cooling power of 20 pW at 80 mK. At present, we are focusing on obtaining similar performance in cooling cryogenic detectors. Additionally, we present recent results of successful operation of a metalsemiconductor structure with a Schottky barrier acting as the tunnel barrier and the possibility to use this kind of structures for on-chip cooling.
Revisiting the electronic properties of Molecular Semiconductor – Doped Insulator (MSDI) heterojunctions through impedance and chemosensing studies
2015
Abstract The core activity of this work was to give a new interpretation of the electronic behavior of Molecular Semiconductor – Doped Insulator heterojunctions (MSDI), a new organic device combining two molecular materials with very different electronic properties. We focused on understanding the phenomenon occurring at the interface of fluorinated and non-fluorinated phthalocyanines that appears to be a determining factor for the electronic charge transport in the two-component thin film and ultimately deciding the nature of gas sensing, as illustrated with ozone and ammonia chosen as examples of accepting and donating gases. The impedance measurements showed that the Schottky contact bet…
Schottky barrier height tuning by Hybrid organic-inorganic multilayers
2014
ABSTRACTSemiconducting and insulating polymers and copolymers/Au nanograins based hybrid multilayers (HyMLs) were fabricated on p-Si single-crystal substrate by an iterative method that involves, respectively, Langmuir-Blodgett and spin-coating techniques (for the deposition of organic film) and sputtering technique (for the deposition of metal nanograins) to prepare Au/HyMLs/p-Si Schottky device. The electrical properties of the Au/HyMLs/p-Si Schottky device were investigated by current-voltage (I–V) measurements in the thickness range of 1-5 bilayers (BL).At different number of layers, current-voltage (I–V) measurements were performed. Results showed a rectifying behavior. Junction parame…