0000000000697724

AUTHOR

Juha Heinonen

showing 16 related works from this author

Results on radiation hardness of black silicon induced junction photodetectors from proton and electron radiation

2020

Abstract The stability of black silicon induced junction photodetectors under high-energy irradiation was tested with 11 MeV protons and 12 MeV electrons using fluence of 1 ⋅ 10 10 protons/cm2 and dose of 67 krad(Si) for protons and electrons, respectively. The energies and dose levels were selected to test radiation levels relevant for space applications. The degradation was evaluated through dark current and external quantum efficiency changes during (within 1 h after each step) and after (some days after) full irradiation sequences. Furthermore, the black silicon photodetectors were compared to planar silicon induced junction and planar silicon pn-junction photodetectors to assess the co…

Nuclear and High Energy PhysicsPassivationSiliconPhysics::Instrumentation and Detectorschemistry.chemical_element02 engineering and technology01 natural scienceschemistry.chemical_compound0103 physical sciencesRadiation damageElectron beam processingIrradiationInstrumentationPhysics010308 nuclear & particles physicsbusiness.industryBlack silicontechnology industry and agricultureequipment and supplies021001 nanoscience & nanotechnologySemiconductorchemistryOptoelectronicsQuantum efficiency0210 nano-technologybusinessNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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Quasiconformal distortion on arcs

1994

Distortion (mathematics)Quasiconformal mappingExtremal lengthPartial differential equationGeneral MathematicsMathematical analysisTopologyAnalysisMathematicsJournal d'Analyse Mathématique
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An introduction to Cheeger's differentiation theory

2015

DifferentiationCalculusMathematics
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Quasiconformal maps in metric spaces with controlled geometry

1998

This paper develops the foundations of the theory of quasiconformal maps in metric spaces that satisfy certain bounds on their mass and geometry. The principal message is that such a theory is both relevant and viable. The first main issue is the problem of definition, which we next describe. Quasiconformal maps are commonly understood as homeomorphisms that distort the shape of infinitesimal balls by a uniformly bounded amount. This requirement makes sense in every metric space. Given a homeomorphism f from a metric space X to a metric space Y , then for x∈X and r>0 set

Quasiconformal mappingMetric spaceGeneral MathematicsInjective metric spaceMetric (mathematics)Metric mapGeometryFubini–Study metricFisher information metricMathematicsConvex metric spaceActa Mathematica
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Quasilines and conformal mappings

1981

Pure mathematicsExtremal lengthPartial differential equationFunctional analysisGeneral MathematicsConformal mapConformal geometryAnalysisMathematicsJournal d'Analyse Mathématique
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Asymptotic paths for subsolutions of quasilinear elliptic equations

1988

Letu be an entire lower semicontinuous subsolution to the quasilinear elliptic equation divA(x,∇u)=0 in ℝn. It is shown that ifu is not bounded above, then there exists a path going to infinity along whichu tends to infinity. The result extends works of Talpur, Fuglede, and others. Growth aspects of subsolutions are also studied.

Path (topology)Elliptic curveNumber theoryGeneral Mathematicsmedia_common.quotation_subjectMathematical analysisAlgebraic geometryInfinityMathematicsGrowth aspectsmedia_commonManuscripta Mathematica
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BLD -mappings in $W^{2,2}$ are locally invertible

2000

We prove that mappings of bounded length distortion are local homeomorphisms if they have L 2 -integrable weak second derivatives.

Discrete mathematicsDistortion (mathematics)Invertible matrixIntegrable systemlawGeneral MathematicsBounded functionMathematics::General TopologySecond derivativeMathematicslaw.inventionMathematische Annalen
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Boundary accessibility and elliptic harmonic measures

1988

Suppose G is a bounded domain in R n such that the complement of G satisfies a capacity dcnsity condition. It is shown that all elliptic measures in G have a support set with Moreover, the capacity density condition cannot be removed. A nonlinear version of the result is also given.

Elliptic operatorNonlinear systemPartial differential equationBounded functionMathematical analysisBoundary (topology)Harmonic (mathematics)General MedicineDomain (mathematical analysis)Complement (set theory)MathematicsComplex Variables, Theory and Application: An International Journal
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Harmonic morphisms in nonlinear potential theory

1992

This article concerns the following problem: given a family of partial differential operators with similar structure and given a continuous mapping f from an open set Ω in Rn into Rn, then when does f pull back the solutions of one equation in the family to solutions of another equation in that family? This problem is typical in the theory of differential equations when one wants to use a coordinate change to study solutions in a different environment.

010308 nuclear & particles physicsGeneral Mathematics010102 general mathematicsHarmonic (mathematics)01 natural sciencesPotential theory30C6535J60AlgebraNonlinear systemMorphism0103 physical sciences0101 mathematicsMathematicsNagoya Mathematical Journal
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Gromov–Hausdorff convergence and Poincaré inequalities

2015

Pure mathematicssymbols.namesakePoincaré conjectureGromov–Hausdorff convergencesymbolsMathematics
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A-superharmonic functions and supersolutions of degenerate elliptic equations

1988

Quarter periodSubharmonic functionNomeGeneral MathematicsMathematical analysisDegenerate energy levelsElliptic functionJacobi elliptic functionsMathematics
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Other definitions of Sobolev-type spaces

2015

Sobolev spacePure mathematicsType (model theory)Mathematics
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Sobolev classes of Banach space-valued functions and quasiconformal mappings

2001

We give a definition for the class of Sobolev functions from a metric measure space into a Banach space. We give various characterizations of Sobolev classes and study the absolute continuity in measure of Sobolev mappings in the “borderline case”. We show under rather weak assumptions on the source space that quasisymmetric homeomorphisms belong to a Sobolev space of borderline degree; in particular, they are absolutely continuous. This leads to an analytic characterization of quasiconformal mappings between Ahlfors regular Loewner spaces akin to the classical Euclidean situation. As a consequence, we deduce that quasisymmetric maps respect the Cheeger differentials of Lipschitz functions …

Discrete mathematicsMathematics::Complex VariablesGeneral MathematicsEberlein–Šmulian theoremMathematics::Analysis of PDEsSobolev inequalitySobolev spaceMathematics::Metric GeometryBesov spaceInterpolation spaceBirnbaum–Orlicz spaceMetric differentialAnalysisMathematicsTrace operator
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Improved stability of black silicon detectors using aluminum oxide surface passivation

2021

Publisher Copyright: © 2021 ESA and CNES We have studied how high-energy electron irradiation (12 MeV, total dose 66 krad(Si)) and long term humidity exposure (75%, 75 °C, 500 hours) influence the induced junction black silicon or planar photodiode characteristics. In our case, the induced junction is formed using n-type silicon and atomic-layer deposited aluminum oxide (Al2O3), which contains a large negative fixed charge. We compare the results with corresponding planar pn-junction detectors passivated with either with silicon dioxide (SiO2) or Al2O3. The results show that the induced junction detectors remain stable as their responsivity remains nearly unaffected during the electron beam…

Materials sciencePassivationalumiinioksidi114 Physical scienceslaw.inventionelektroniikkakomponentitPhotodiodechemistry.chemical_compoundlawpuolijohteetphotodiodeIrradiationAluminum oxidebusiness.industryionisoiva säteilyBlack siliconDetectorblack siliconBlack siliconHumidityHumidityPhotodiodechemistrysäteilyfysiikkailmaisimetOptoelectronicsIrradiationbusinessilmankosteuspiidioksidi
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Lectures on Lipschitz analysis

2005

Lipschitz analysisgeometriaLipschitz analyysigeometrinen analyysi
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Geometric embeddings of metric spaces

2003

geometrialaskentamenetelmät
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