1,721,179 research outputs found
Two-Dimensional Numerical Simulation of Deep Level Effect in 6H-SiC Buried-Gate JFETs
No full textIn this paper deeplevel eects are investigated in HSiC buried gate nchannel JFETs by means of mea
surements and simulations of the draincurrent ID transients following a gatetosource voltage VGS step
Deep levels present in the JFETs are detected by means of capacitancemode C and currentmode I Deep
Level Transient Spectroscopy DLTS Subsequent simulation of the ID transients allows the energetic and spatial
position of the dierent deep levels to be inferre
Compact Modeling of N-Side Interstrip Resistance in P-Stop and P-Spray Isolated Double-Sided Silicon Microstrip Detectors
No full textNumerical Simulation of Efficiency-Droop Mechanisms in InGaN/GaN Blue Light-Emitting Diodes
No full textWe will report on a systematic analysis of above aspects carried out by means of numerical device simulations. The aims of this analysis are (i) to improve understanding of droop mechanisms, (ii) to provide guidelines for LED optimization. Specific results will address 1) the suitability of pure droop mechanisms and/or the combination of 2 or more mechanisms to explain the droop, 2) the effects of above technological changes on IQE vs current curve
Failure Physics and Reliability of GaN-Based optoelectronic devices
No full textWith this work we review the failure modes and mechanisms of GaN-based optoelectronic devices. A number of reliability tests are presented and specific degradation mechanisms of state-of-the-art optoelectronic devices are analyzed. In particular, we describe recent results concerning (i) the degradation of the active layer of LEDs and lasers, due to the increase in non-radiative recombination; (ii) the degradation of LEDs submitted to reverse-bias stress tests; (iii) the catastrophic failure of advanced LED structures, related to Electrostatic Discharge (ESD) events; (iv) the degradation of the ohmic contacts of GaN-based LEDs; (v) the degradation of the optical properties of the package/phosphors system of white LEDs. The presented results provide important information on the weaknesses of LED technology and on the design of procedures for reliability evaluation. Results are compared with literature data throughout the presentation
Analytical Model for the Ohmic-Side Interstrip Resistance of Double-Sided Silicon Microstrip Detectors
No full textA compact, analytical model is derived for the n-side interstrip resistance of double-sided silicon microstrip detectors, allowing for fast and accurate prediction of the minimum p-stop (or p-spray) implant dose ensuring adequate interstrip isolation. The basic idea on which the proposed model relies is that the portion of the detector between two adjacent n-strips can effectively be reduced to an equivalent n-channel MOSFET. The interstrip resistance can be evaluated as the output resistance of this equivalent MOSFET using standard SPICE-like models. The influence of radiation-induced oxide charge and p-stop (or p-spray) voltage can be accounted for, by simply including into the threshold voltage expression, the induced flat-band voltage shift and body-effect term, respectivel
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
