Search results for "Transient measurements"

showing 2 items of 2 documents

Temperature and time dependent electron trapping in Al2O3 thin films onto AlGaN/GaN heterostructures

2022

In this article, the charge trapping phenomena in Al2O3 thin films grown by atomic layer deposition (ALD) on AlGaN/GaN heterostructures have been studied by time-dependent capacitance–voltage (C-V) measurements as a function of temperature. In particular, monitoring the transient of the capacitance enabled us to estimate the maximum depth of the insulating layer interested by the negative charge trapping effect under our bias stress conditions and to determine a charge traps density in the bulk Al2O3 in the order of 3 × 1019 cm−3. A temperature dependent C-V analysis up to 150 °C demonstrated the presence of two competitive mechanisms that rule the electron capture and emission in the Al2O3…

Capacitance transient measurementsCharge trappingAl2O3General Physics and AstronomyGallium nitrideSurfaces and InterfacesGeneral ChemistryCondensed Matter PhysicsPlasma enhanced atomic layer depositionSurfaces Coatings and FilmsApplied Surface Science
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A Study on the Measurement Instrumentation for a Custom-Made Bipendulum Impact Testing Machine

2008

Experimental investigations of structures under impact loads are normally carried out by means of drop-weight testing rigs, which are often tailor made, and require sensors for fast transient measurement of mechanical quantities (namely, force, displacement, velocity, and absorbed energy). Since these tests are quite expensive, time consuming, and, often, not repeatable, the sensors must provide reliable and interpretable results in the first trial. In this paper, a thorough study on the measurement instrumentation suitable to carry out reliable low-velocity impact tests by means of a custom-made bipendulum impact testing machine is presented. Attention has been focused on the choice of the…

Piezoelectric transducersComputer scienceImpact measurements; Instrumented impact testing; Optical velocity sensors; PVDF force sensors; Piezoelectric transducers; Transient measurementsImpact measurementsMechanical engineeringAccelerometerLoad cellFriction lossDynamic load testingTransducerOptical velocity sensorsElectronic engineeringCalibrationPVDF force sensorsTransient measurementsInstrumentation (computer programming)Electrical and Electronic EngineeringImpactInstrumentationInstrumented impact testing
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