1 Ocak 2019 Dergi makalesi Açık Erişim

Rut, Fabian; Aygueler, Lieitem F.; Giesbrecht, Nadja; Rendenbach, Bettina; Magin, Alice; Docampo, Pablo; Kait, Heinz; Hetterich, Michael

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{
  "@context": "https://schema.org/", 
  "@id": 74299, 
  "@type": "ScholarlyArticle", 
  "creator": [
    {
      "@type": "Person", 
      "affiliation": "KIT, Inst Appl Phys, D-76131 Karlsruhe, Germany", 
      "name": "Rut, Fabian"
    }, 
    {
      "@type": "Person", 
      "name": "Aygueler, Lieitem F."
    }, 
    {
      "@type": "Person", 
      "name": "Giesbrecht, Nadja"
    }, 
    {
      "@type": "Person", 
      "affiliation": "Ludwig Maximilians Univ Munchen, Dept Chem, D-81377 Munich, Germany", 
      "name": "Rendenbach, Bettina"
    }, 
    {
      "@type": "Person", 
      "affiliation": "KIT, Inst Appl Phys, D-76131 Karlsruhe, Germany", 
      "name": "Magin, Alice"
    }, 
    {
      "@type": "Person", 
      "affiliation": "Newcastle Univ, Sch Elect & Elect Engn, Dept Phys, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England", 
      "name": "Docampo, Pablo"
    }, 
    {
      "@type": "Person", 
      "affiliation": "KIT, Inst Appl Phys, D-76131 Karlsruhe, Germany", 
      "name": "Kait, Heinz"
    }, 
    {
      "@type": "Person", 
      "name": "Hetterich, Michael"
    }
  ], 
  "datePublished": "2019-01-01", 
  "description": "Multiple-cation mixed-halide (Cs,FA,MA)Pb(I,Br)(3) perovskites containing cesium, formarnidinium (FA), and methylammonium (MA) possess excellent properties for a wide range of optoelectronic applications such as thin-film pliotovoltaics or lasers. We investigate the role of excitons and the excitor) binding energy E-B, relevant for the effectiveness of charge separation in solar cells, as well as the temperature dependent bandgap energy E-g which is used as an indicator for crystal phase transitions. Generalized Elliott fits of absorption spectra offer the possibility to determine both E-B and E-g. However, since excitonic effects are non-negligibk even at room temperature, a careful and detailed analysis of the spectra is crucial for a correct interpretation. Therefore, an additional evaluation based on a so-called f-sum rule is applied to achieve an improved reliability of the results at higher temperatures. The obtained EB values of 20-24 meV for Cs-contailaing mixed perovskite compounds are below the ones of 24-32 meV and 36-41 meV for pure methylammonium lead iodide (MAPbI(3)) and bromide (MAPbBr(3)), respectively, and, thus, facilitate charge-carner separation in photovoltaic applications. Furthermore, temperature-dependerit (T = 5-300 K) studies of E-g in (Cs,FA,MA)Pb(I,BrP)(3) indicate a suppressed crystal phase transition by the absence of any phase-transition related signatures such as the well-Imown jump of about 100 meV in MAPbI(3). We verify these results using temperature-dependent electroreflectance spectroscopy, which is a very reliable technique for the direct and non-destructive determination of optical resonances of the absorber layer in complete solar cells. Additionally, we confirm the suppression i of the phase transition in Cs-0.05(FA(0.83)MA(0.17))(0.95)Pb(I0.83Br0.17)(3) by ternperature-deperiderit X-ray diffraction. (C) 2019 Author(s).", 
  "headline": "Temperature-dependent studies of excitors binding energy and phase-transition suppress on in (Cs,FA,MA)Pb(I,Br)(3) perovskites", 
  "identifier": 74299, 
  "image": "https://aperta.ulakbim.gov.tr/static/img/logo/aperta_logo_with_icon.svg", 
  "license": "http://www.opendefinition.org/licenses/cc-by", 
  "name": "Temperature-dependent studies of excitors binding energy and phase-transition suppress on in (Cs,FA,MA)Pb(I,Br)(3) perovskites", 
  "url": "https://aperta.ulakbim.gov.tr/record/74299"
}