Search results for "Deep trap"

showing 3 items of 3 documents

Study of voltage decrease in organic light emitting diodes during the initial stage of lifetime

2016

Abstract We report the results of lifetime DC testing at constant current of not-encapsulated organic light emitting diodes (OLEDs) based on Tris (8 idroxyquinoline) aluminum (Alq3) as emitting material. In particular, a voltage decrease during the initial stage of the lifetime test is observed. The cause of this behavior is also discussed, mainly linked to initial Joule self-heating of the device, rising its temperature above room temperature until thermal equilibrium is reached at steady state.

Organic light emitting diodes (OLEDs)Lifetime testingMaterials scienceAlq3chemistry.chemical_elementJoule02 engineering and technologySettore ING-INF/01 - Elettronica01 natural sciencesAluminium0103 physical sciencesMaterials ChemistryOLEDElectrical and Electronic Engineering010302 applied physicsThermal equilibriumSteady statebusiness.industryJoule heating021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialschemistryOptoelectronicsConstant current0210 nano-technologybusinessJoule heatingDeep trapVoltageSolid-State Electronics
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Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers

2020

The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the high temperature GaN buffer and the QW region. Capacitance-voltage profiling with monochromatic illumination showed that in the InGaN underlayer (UL), the density of deep traps with optical threshold near 1.5 eV was much higher than in the QW and higher than for structures without InGaN. Irradiation with 5 MeV electrons strongly increased the concentration of these 1.5 eV traps in the QWs, with the increase more pronounced for samples witho…

electronMaterials scienceDeep-level transient spectroscopy02 engineering and technologyElectronTrapping010402 general chemistrySettore ING-INF/01 - Elettronica01 natural sciencesSettore FIS/03 - Fisica Della MateriaSpectral linelaw.inventionInGaN underlayerRadiation tolerancelawMaterials ChemistryIrradiationInGaN/GaN single quantum well structuresdefectsQuantum wellbusiness.industryMechanical Engineeringlight-emitting-diodesMetals and Alloys021001 nanoscience & nanotechnologyn/a OA procedure0104 chemical sciencesefficiencyMechanics of MaterialsOptoelectronics0210 nano-technologybusinessDeep traps in nitride semiconductorperformanceLight-emitting diodeJournal of Alloys and Compounds
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Effects of InAlN underlayer on deep traps detected in near-UV InGaN/GaN single quantum well light-emitting diodes

2019

Two types of near-UV light-emitting diodes (LEDs) with an InGaN/GaN single quantum well (QW) differing only in the presence or absence of an underlayer (UL) consisting of an InAlN/GaN superlattice (SL) were examined. The InAlN-based ULs were previously shown to dramatically improve internal quantum efficiency of near-UV LEDs, via a decrease in the density of deep traps responsible for nonradiative recombination in the QW region. The main differences between samples with and without UL were (a) a higher compensation of Mg acceptors in the p-GaN:Mg contact layer of the sample without UL, which correlates with the presence of traps with an activation energy of 0.06 eV in the QW region, (b) the…

electronMaterials scienceSuperlatticeGeneral Physics and Astronomy02 engineering and technologyElectronElectroluminescenceSettore ING-INF/01 - Elettronica01 natural sciencesganSettore FIS/03 - Fisica Della Materialaw.inventionlaw0103 physical sciencesIrradiationQuantum wellDiode010302 applied physicsbusiness.industry021001 nanoscience & nanotechnologyefficiencyInAlN underlayer effects Deep traps InGaN/GaN single quantum well light-emitting diodesOptoelectronicsQuantum efficiency0210 nano-technologybusinessLight-emitting diodeJournal of Applied Physics
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