| 1. |
- Berggren, Elin, et al.
(författare)
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Charge Transfer in the P(g42T-T) : BBL Organic Polymer Heterojunction Measured with Core-Hole Clock Spectroscopy
- 2023
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 127:49, s. 23733-23742
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Tidskriftsartikel (refereegranskat)abstract
- The conductivity of organic polymer heterojunction devices relies on the electron dynamics occurring along interfaces between the acceptor and donor moieties. To investigate these dynamics with chemical specificity, spectroscopic techniques are employed to obtain localized snapshots of the electron behavior at selected interfaces. In this study, charge transfer in blends (by weight 10, 50, 90, and 100%) of p-type polymer P(g(4)2T-T) (bithiophene-thiophene) and n-type polymer BBL (poly(benzimidazo-benzo-phenanthroline)) was measured by resonant Auger spectroscopy. Electron spectra emanating from the decay of core-excited states created upon X-ray absorption in the donor polymer P(g(4)2T-T) were measured in the sulfur KL2,3L2,3 Auger kinetic energy region as a function of the excitation energy. By tuning the photon energy across the sulfur K-absorption edge, it is possible to differentiate between decay paths in which the core-excited electron remained on the atom with the core-hole and those where it tunneled away. Analyzing the competing decay modes of these localized and delocalized (charge-transfer) processes facilitated the computation of charge-transfer times as a function of excitation energy using the core-hole clock method. The electron delocalization times derived from the measurements were found to be in the as/fs regime for all polymer blends, with the fastest charge transfer occurring in the sample with an equal amount of donor and acceptor polymer. These findings highlight the significance of core-hole clock spectroscopy as a chemically specific tool for examining the local charge tunneling propensity, which is fundamental to understanding macroscopic conductivity. Additionally, the X-ray absorption spectra near the sulfur K-edge in the P(g(4)2T-T) polymer for different polymer blends were analyzed to compare molecular structure, orientation, and ordering in the polymer heterojunctions. The 50% donor sample exhibited the most pronounced angular dependence of absorption, indicating a higher level of ordering compared to the other weight blends. Our studies on the electron dynamics of this type of all-polymer donor-acceptor systems, in which spontaneous ground-state electron transfer occurs, provide us with critical insights to further advance the next generation of organic conductors with mixed electron-hole conduction characteristics suitable for highly stable electrodes of relevance for electronic, electrochemical, and optoelectronic applications.
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| 2. |
- Hellsmark, Hans, 1974, et al.
(författare)
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Teknologiska innovationssystem inom energiområdet: En praktisk vägledning till identifiering av systemsvagheter som motiverar särskilda politiska åtaganden
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med denna rapport är att illustrera hur ett praktiskt inriktat ramverk, tekno- logiska innovationssystem (TIS), kan användas av analytiker och beslutsfattare vid departement och myndigheter för att analysera strategiskt viktiga teknikområden ?????????????????????????????????????????????????????????????????????????????I rapporten analyseras fem TIS centrerade kring havsbaserad vindkraft, marin energi, ????????????????????????????????????????????????????????????????????????????????????? systemsvagheter som bromsar områdets vidare utveckling, vilka som kan åtgärdas av systemets aktörer och vilka som motiverar särskilda politiska åtaganden. Rapporten utgör därmed ett underlag för att formulera åtgärder för att åstadkomma ökad innova- tion, teknikspridning och industrialisering inom ovan nämnda teknikområden.Studien har även möjliggjort en jämförande analys av likheter och skillnader ???????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????????????????????????????? mellan områdena – de är starka respektive svaga av olika orsaker. Detta visar att ???????????????????????????????????????????????????????????????????????Samtidigt har områdena gemensamma drag. Systemets aktörer, där även politiska ???????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????????????????????- skapsnätverk. Men de har varit sämre på att skapa tidiga nischmarknader som ger utrymme för fortsatt lärande och kostnadsreduktion. Sådana nischer kan ibland skapas av marknadens aktörer, men ofta krävs politiska styrmedel. De behövs för att investeringar i kunskapsutveckling ska kunna nyttiggöras och för att en bred industriell utveckling inom nya områden skall göras möjlig i Sverige.Vidare presenteras lärdomar kring vad en aktiv teknikpolitik innebär. Två huvud- ??????????????????????????????????????????????????????????????????????????????- hällsbygget och därför bör vara ett politikområde bland många samt att den skarpa ??????????????????????????????????????????????????????????????????????????????- ?????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????????????????????????? olika faser av innovationssystemets utveckling.För att lyckas med en aktiv teknikpolitik behövs en hög grad av koordinering ??????????????????????????????????????????????????????????????????????? teknikområden så att ”rätt” typ av åtgärder kan sättas in vid ”rätt” tidpunkt av ”rätt” aktör. TIS-ramverket lyfts här fram som en metod för att skapa ett sådant underlag. Slutligen presenteras en metod för projektbedömningar som syftar till att stötta handläggare i utvärderingar av projekt inom nya teknikområden.Rapporten i sin helhet riktar sig särskilt till beslutsfattare och handläggare vid myndigheter, departement och politiker, men även andra organisationer och indi- vider med intresse av att högt ställda klimatmål ska kunna nås samtidigt som en positiv näringslivsutveckling möjliggörs.
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| 3. |
- Abdallah, J, et al.
(författare)
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Rapidity-alignment and p(T) compensation of particle pairs in hadronic Z(0) decays
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 533:3-4, s. 243-252
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Tidskriftsartikel (refereegranskat)abstract
- Observation is made of rapidity-alignment of K+K- and (p) over barp pairs which results from their asymmetric orientation in rapidity, with respect to the direction from primary quark to antiquark. The K+K- and (p) over barp data are consistent with predictions from the fragmentation string model. However, the (p) over barp data strongly disagree with the conventional implementation of the cluster model. The non-perturbative process of 'gluon splitting to diquarks' has to be incorporated into the cluster model for it to agree with the data. Local conservation of PT between particles nearby in rapidity (i.e., p(T) compensation) is analysed with respect to the thrust direction for pi(+)pi(-), K+K-, and (p) over barp pairs. In this case, the string model provides fair agreement with the data. The cluster model is incompatible with the data for all three particle pairs. The model with its central premiss of isotropically-decaying clusters predicts a p(T) correlation not seen in the data. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 4. |
- Abdallah, J, et al.
(författare)
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Search for charged Higgs bosons in e(+)e(-) collisions root s=189-202 GeV
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 17-28
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Tidskriftsartikel (refereegranskat)abstract
- A search for pair-produced charged Higgs bosons was performed in the high energy data collected by the DELPHI detector at LEP II at centre-of-mass energies from 189 GeV to 202 GeV. The three different final states, taunutaunu, c (s) over bar(c) over bars and c (s) over bar taunu were considered. New methods were applied to reject wrong hadronic jet pairings and for the tau identification, where a discriminator based on tau polarisation and polar angles was used. No excess of data compared to the expected Standard Model processes was observed and the existence of a charged Higgs boson with mass lower than 71.5 GeV/c(2) is excluded at the 95% confidence level. (C) 2002 Published by Elsevier Science B.V.
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| 5. |
- Abdallah, J, et al.
(författare)
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Searches for neutral Higgs bosons in e(+)e(-), collisions from root s=191.6 to 201.7 GeV
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 23:3, s. 409-435
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Tidskriftsartikel (refereegranskat)abstract
- Neutral Higgs bosons of the Standard Model (SM) and the Minimal Supersymmetric Standard Model (MSSM) were searched for in the data collected in 1999 by the DELPHI experiment at centre-of-mass energies between 191.6 and 201.7 GeV with a total integrated luminosity of 228 pb(-1). These analyses, in combination with our results at lower energies, set 95% confidence level lower mass bounds on the Standard Model Higgs boson (107.3 GeV/c(2)) and on the lightest neutral scalar (85.9 GeV/c(2)) and neutral pseudoscalar (86.5 GeV/c(2)) Higgs bosons in representative scans of the MSSM parameter space. An extended scan of the MSSM parameter space was also performed to test the robustness of these limits.
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| 6. |
- Abreu, P, et al.
(författare)
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b-tagging in DELPHI at LEP
- 2004
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 32:2, s. 185-208
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Tidskriftsartikel (refereegranskat)abstract
- The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly.
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